Maldigestion: impaired breakdown of nutrients
(carbohydrates, protein, fat) to absorbable split-
products (mono-, di-, or oligosaccharides; amino
acids; oligopeptides; fatty acids;
Malabsorption: defective mucosal uptake and
transport of adequately digested nutrients
including vitamins and trace elements.
Malabsorption Syndrome is a clinical term that
encompasses defects occurring during the
digestion and absorption of food nutrients by
the gastrointestinal tract
The digestion or absorption of a single nutrient
component may be impaired, as in lactose
intolerance due to lactase deficiency.
However, when a diffusion disorder, such as
celiac disease or Crohn's disease, affects the
intestine, the absorption of almost all nutrients is
In general, the digestion and absorption of food
materials can be divided into 3 major phases:
Post - absorptive.
The luminal phase is the phase in which dietary fats,
proteins, and carbohydrates are hydrolyzed and
solubilized by secreted digestive enzymes and bile.
The mucosal phase relies on the integrity of the
brush-border membrane of intestinal epithelial cells
to transport digested products from the lumen into
In the post - absorptive phase, reassembled lipids
and other key nutrients are transported via
lymphatic and portal circulation from epithelial cells
to other parts of the body.
The best way to classify the numerous causes of
malabsorption is to consider the 3 phases of
digestion and absorption.
Impaired nutrient hydrolysis
The most common cause for impaired nutrient
hydrolysis is pancreatic insufficiency due to
chronic pancreatitis, pancreatic resection,
pancreatic cancer, or cystic fibrosis. The resultant
deficiencies in lipase and proteases lead to lipid
and protein malabsorption, respectively.
Inactivation of pancreatic enzymes by gastric
hypersecretion, as seen in Zollinger-Ellison
syndrome, is another cause.
Inadequate mixing of nutrients, bile, and
pancreatic enzymes, as seen in rapid intestinal
transit, gastrojejunostomy, total and partial
gastrectomy, or intestinal resection after
mesenteric emboli or thrombosis, also causes
Rarely, a failure to convert a proenzyme to active
form, such as enterokinase and trypsinogen
deficiencies, also can cause protein maldigestion
Impaired micelle formation
Impaired micelle formation causes a problem in fat
solubilization and subsequent fat malabsorption.
This impairment is due to different reasons,
(1) decreased bile salt synthesis from severe
parenchymal liver disease (eg, cirrhosis);
(2) impaired bile secretion from biliary obstruction or
cholestatic jaundice (eg, primary biliary cirrhosis,
primary sclerosing cholangitis);
(3) impaired enterohepatic bile circulation, as seen in
small bowel resection or regional enteritis; or
(4) bile salt deconjugation due to small bowel bacterial
Stasis of intestinal content caused by a motor
abnormality (eg, scleroderma, diabetic
neuropathy, intestinal obstruction), an anatomic
abnormality (eg, small bowel syndrome,
stricture, ischemia, blind loops), or small bowel
contamination from enterocolonic fistulas can
cause bacterial overgrowth.
Luminal availability and processing
Luminal bacterial overgrowth can cause a
decrease in the availability of substrates,
including carbohydrates, proteins, and vitamins
(eg, vitamin B-12, folate).
Vitamin B-12 deficiency due to pernicious
anemia is caused by a lack of intrinsic factor
and by pancreatic enzyme deficiency.
Impaired brush-border hydrolase activity
Disaccharidase deficiency can lead to disaccharide
Lactase deficiency, either primary or secondary, is
the most common form of disaccharidase deficiency.
Genetic factors determine primary lactase deficiency.
Secondary lactase deficiency can be due to acute
gastroenteritis (rotavirus and giardia infection),
chronic alcoholism, celiac sprue, radiation enteritis,
regional enteritis, or AIDS enteropathy.
Immunoglobulin A (IgA) deficiency (most common
immunodeficiency) is due to decreased or absent
serum and intestinal IgA, which clinically appears
similar to celiac disease and is unresponsive to a
Acrodermatitis enteropathica is an autosomal
recessive disease with selective inability to absorb
zinc, leading to villous atrophy and acral dermatitis.
Autoimmune enteropathy primarily diagnosed in
children presenting with intractable secretory
diarrhea and villous atrophy. Autoimmune
enteropathy is due to antibodies directed against
intestinal epithelial and goblet cells. Additional cell
types affected by auto antibodies include islet and
Other carbohydrase deficiencies, such as sucrase-
isomaltase deficiency, may be the cause.
Impaired nutrient absorption
Nutrient malabsorption is due to inherited or
Inherited defects include glucose-galactose
malabsorption, abetalipoproteinemia, cystinuria, and
Acquired disorders are far more common and are
caused by the following:
(1) decreased absorptive surface area, as seen in
intestinal resection of intestinal bypass;
(2) damaged absorbing surface, as seen in celiac sprue,
tropical sprue, Crohn's disease, AIDS enteropathy,
chemotherapy, or radiation therapy;
(3) infiltrating disease of the intestinal wall, such as
lymphoma and amyloidosis; and
(4) infections, including bacterial overgrowth,
giardiasis, Whipple's disease, cryptosporidiosis, and
Obstruction of the lymphatic system, both
congenital (eg, intestinal lymphangiectasia,
Milroy disease) and acquired (eg, Whipple
disease, neoplasm [including lymphoma],
tuberculosis), impairs the absorption of
chylomicrons and lipoproteins and may cause
fat malabsorption or a protein-losing
Factors that may increase your chance of having
Medical conditions affecting the intestine
Use of laxatives
Excessive use of antibiotics
Excessive use of alcohol
Travel to countries with high incidence of
The osmotic load resulting from the inability of
the intestine to absorb certain nutrient elements
causes the presenting symptoms. On occasion, the
products of digestion produced by bacterial flora
also result in a secretory reaction by the intestine.
Diarrhea is the most common symptomatic
Diarrhea frequently is watery, reflecting the
osmotic load received by the intestine.
Bacterial action producing hydroxy fatty
acids from undigested fat also can increase
net fluid secretion from the intestine, further
worsening the diarrhea.
Steatorrhea is the result of fat malabsorption.
The hallmark of steatorrhea is the passage of
pale, bulky, and malodorous stools.
Such stools often float on top of the toilet
water and are difficult to flush. Also, patients
find floating oil droplets in the toilet
Weight loss and fatigue
Weight loss is common and may be
pronounced; however, patients may
compensate by increasing their caloric
consumption, masking weight loss from
The chance of weight loss increases in
diffusion diseases involving the intestine,
such as celiac disease and Whipple disease.
Flatulence and abdominal distention
Bacterial fermentation of unabsorbed food
substances releases gaseous products, such as
hydrogen and methane, causing flatulence.
Flatulence often causes uncomfortable
abdominal distention and cramps.
Hypoalbuminemia from chronic protein
malabsorption or from loss of protein into the
intestinal lumen causes peripheral edema.
Extensive obstruction of the lymphatic
system, as seen in intestinal
lymphangiectasia, can cause protein loss.
With severe protein depletion, ascites may
Depending on the cause, anemia resulting
from malabsorption can be either microcytic
(iron deficiency) or macrocytic (vitamin B-12
Iron deficiency anemia often is a
manifestation of celiac disease.
Ileal involvement in Crohn disease or ileal
resection can cause megaloblastic anemia due
to vitamin B-12 deficiency.
Bleeding usually is a consequence of vitamin
K malabsorption and subsequent
Ecchymosis usually is the manifesting
symptom, although, occasionally, melena
and hematuria occur.
Metabolic defects of bones
Vitamin D deficiency can cause bone
disorders, such as osteopenia or
Bone pain and pathologic fractures may be
Malabsorption of calcium can lead to
Electrolyte disturbances, such as hypocalcemia
and hypomagnesemia, can lead to tetany,
manifesting as the Trousseau sign and the
Vitamin malabsorption can cause generalized
motor weakness (pantothenic acid, vitamin D)
or peripheral neuropathy (thiamine), a sense of
loss for vibration and position (cobalamin),
night blindness (vitamin A), and seizures
Patients may have orthostatic hypotension.
Patients may complain of fatigue.
Signs of weight loss, muscle wasting, or both
may be present.
Patients may have signs of loss of
The abdomen may be distended, and bowel
sounds may be hyperactive.
Ascites may be present in severe
Pale skin may reveal anemia.
Ecchymoses due to vitamin K deficiency may be
Dermatitis herpetiformis, erythema nodosum,
and pyoderma gangrenosum may be present.
Pellagra, alopecia, or seborrheic dermatitis may
Neurologic al manifestation
Motor weakness, peripheral neuropathy, or
ataxia may be present.
The Chvostek sign or the Trousseau sign may
be evident due to hypocalcemia or
Cheilosis, glossitis, or aphthous ulcers of the
Long-term malabsorption can result in:
Osteoporosis and bone disease
Malnutrition and vitamin deficiencies
Celiac disease is a digestive disorder. It is caused
by an immune reaction to gluten. Celiac disease is
also known as:
Non - tropical sprue
Celiac disease (CD) is an immune-mediated disorder, the
only one with a well-established origin, resulting from a
permanent gluten intolerance, which primarily involves the
It is characterized by the presence of chronic inflammation
of the small bowel’s mucosa and submucosa, and is clinically
characterized by the presence of diverse systemic
It may start at any age, both during childhood and
adolescence, and is also relatively common in adulthood.
It is being increasingly diagnosed even in elderly patients (up
to 20% of patients are older than 60 years, at the time of
The causative agent, gluten, is well established; a mixture
of proteins present exclusively in cereals –mainly
wheat, barley, rye and oats- but not corn.
It affects only predisposed individuals, whose most
susceptible genetic features are related to human leukocytes
antigens from class two (HLA-), predominantly HLA-DQ2
(90%), while much less frequency HLA-DQ8 (5%-10%).
However, these genetic markers are a necessary, but not
a sufficient condition, since a significant frequency of
CD patients (5%-10%) are DQ2 and DQ8-negative. This
means that other, still not well-established, genotypes
may exist that probably correspond to the class one HLA
system (HLA-), including MICA, MICB and others.
A strong genetic susceptibility is present with about
75% concordance rate, among monozygotic twins. Certain
populations have an increased prevalence of CD. For
instance, the first-degree relatives of individuals with
biopsy-proven CD, have a prevalence between 4%-12% of
those suffering from this disease.
Second-degree relatives also appear to have an increased
prevalence. Patients with type 1 diabetes mellitus (IDDM)
have a prevalence of CD ranging to 3%-8%. In Down´s
syndrome, the presence of CD is found between 5%-12%.
Also, CD is associated with Turner’s and William’s
syndromes, IgA deficiency and several autoimmune
People suffering from other immune diseases and certain genetic
disorders are more likely to have celiac disease. Some disorders
associated with celiac include:
type 1 diabetes
autoimmune liver disease
The triggers for CD are specific immunogenic peptides
that are present only and exclusively in the dietary gluten
proteins, from wheat and similar structural cereals such as
rye and barley. These peptides are resistant to digestion by
gastric and pancreatic enzymes and find their way into the
lamina propria of the small bowel, presumably after some
changes occur in the intercellular tight junctions with an
increase in the intestinal permeability.
One such peptide is a 33-amino acid sequence, which is
a potent activator of specific T-cell lines from patients
The subsequent infiltration by CD4 (+) T
Lymphocytes into the lamina propria and CD8 (+)
into the intestinal epithelium, are a hallmark of
The recognition of HLA-bound gluten peptides by
T cells, leads to their activation and clonal expansion
of B cells that produce antibodies. Other cytokines
released by activated CD4 T cells that involve the
adaptive immune response, promote various
inflammatory mechanisms and produce the
Less information is available on the activation
and mode of action of intraepithelial T cells,
which are mediated by the innate immune
system. The expression of the interleukin-15
cytokine appears to play a central role in driving
various processes that lead to the increased
number of intraepithelial lymphocytes (IELs) as
well as in the destruction process of the
epithelial cells and the mucosal damage
Tissue transglutaminase 2 (tTG), plays an important
role in the immune response and is present in several
tissues in the body. The cross-linking activity of tTG
is involved in several functions, such as wound healing,
formation of cell envelopes in apoptosis and
Stabilization of the extra-cellular matrix. In addition,
this enzyme can deaminate glutamine residues.
Glutamine-rich gluten peptides are, therefore, excellent
substrates for tTG. The resulting deaminated and thus,
negatively-charged peptides, have much higher affinity
for the HLA-DQ2 and DQ8 molecules, and have a key
step in the immune response in CD.
Risk groups and associated disorders
First degree relatives
Down´s and turner´s syndromes
IgA selective deficiency
o Type 1 diabetes mellitus
o Autoimmune thyroid diseases
o Alopecia areata
o Cerebellar ataxia
o Peripheral neuropathy
o Multiple sclerosis
o Primary biliary cirrhosis
o Autoimmune hepatitis
o Autoimmune cholangitis
o Idiopathic hypertransaminasemia
o Rheumatoid arthritis
o Sjögren´s syndrome
o Idiopathic dilated cardiomyopathy
o Autoimmune myocarditis
o Dermatitis herpetiformis
o Iron-deficiency anemia
o Increased risk of fractures
o Dental enamel defects
o Depression and anxiety
o Chronic asthenia
Until the last decade, CD was considered to be
a rare disease, but today it is known to be
universally distributed, to involve all races, and
it is one of the most commonly known genetic
diseases, with a mean prevalence of 1%-2% in
the general population, being clearly
underestimated and under diagnosed
The clinical presentation of CD varies greatly, ranging
from asymptomatic to severely malnourished patients.
The most common clinical manifestations of CD
include abdominal cramping pain with moderate to
severe abdominal distension, frequently associated with
relapsing or permanent dyspepsia, presence of gastro-
Esophageal reflux (GERD) and recurrent episodes of
altered bowel habits (diarrhea and/or constipation),
weight loss, bone disease, anemia and weakness.
While diarrhea was almost considered a
persistent symptom, this is not the case in adults,
and up to 50% of patients predominantly have
constipation, which on many occasions becomes
refractory to all types of therapy.
It should be noted, that up to 30% of celiac
patients have increased body mass index (BMI)
and obvious obesity at diagnosis.
CD is sometimes divided into clinical subtypes. The
terms “symptomatic or classic” apply to cases that meet
the typical features described above.
By contrast, in the “atypical forms” of the disease, the
Gastrointestinal symptoms may be absent or less
pronounced, and in this case the extra-intestinal features
predominate, such as chronic iron deficiency anemia,
osteoporosis, short stature or failure to thrive, infertility and
increased number of abortions.
Since atypical presentations are found more frequently
in later decades, CD is now considered to be a
multisystemic disorder, rather than a sole gastrointestinal
Diarrhea is the most common symptom in
untreated celiac sprue and present in 45-85% of
all patients. Diarrhea caused by celiac sprue is
due to maldigestion and malabsorption of
nutrients. The stools might be watery or
semiformed, light tan or gray, and oily or
frothy. The stools have a characteristic foul
odor. In infants and young children, extensive
diarrhea can lead to severe dehydration,
electrolyte depletion, and metabolic acidosis.
Malabsorption of ingested fat (steatorrhea)
results in the delivery of excessive dietary fat to
the large bowel. This results in the production
of hydroxy fatty acids by bacteria, which
causes secretion of fluids into the intestine.
Flatulence (28% of patients) and borborygmus
(35-72% of patients) results from the release of
intestinal gas by the bacterial florae feasting on
undigested and unabsorbed food materials and
often becomes excessive or even explosive.
Weight loss (present in 45% of all patients) is variable
because some patients might compensate for the
malabsorption by increasing dietary intake. In infants
and young children with untreated celiac sprue, failure to
thrive and growth retardation are common.
Weakness and fatigue (prevalence 78-80%) are usually
related to general poor nutrition. In some patients, severe
anemia can contribute to fatigue. Occasionally, severe
hypokalemia due to the loss of potassium in the stool can
cause muscle weakness.
Severe abdominal pain (prevalence 34-64%) is unusual in
patients with uncomplicated celiac sprue. However,
abdominal bloating or cramps with excessive malodorous
flatus is a common complaint.
Anemia (10-15% of patients) is usually due to
impaired absorption of iron or folate from the
proximal small intestine. In severe celiac
disease with ileal involvement, absorption of
vitamin B-12 might be impaired.
A bleeding diathesis is usually caused by
prothrombin deficiency due to impaired
absorption of fat-soluble vitamin K.
Osteopenia and osteoporosis (prevalence 1-
34%) might cause bone pain for several
reasons, including defective calcium transport
by the diseased small intestine, vitamin D
deficiency, and binding of luminal calcium and
magnesium to unabsorbed dietary fatty acids.
Neurologic symptoms (frequency 8-14%) that
result from hypocalcaemia include motor
weakness, paresthesias with sensory loss, and
ataxia. Seizures might develop because of
Skin disorders, including dermatitis
herpetiformis (a pruritic papulovesicular skin
lesion involving the extensor surfaces of the
extremities, trunk, buttocks, scalp, and neck), is
associated in 10-20% of patients with celiac
Hormonal disorders, such as amenorrhea,
delayed menarche, and infertility in women
and impotence and infertility in men, have
Abdominal examination shows a protuberant
and tympanic abdomen due to distention of
intestinal loops with fluids and gas. Ascites
occasionally can be detected in patients with
Evidence of weight loss, including muscle
wasting or loose skin folds
Hyperkeratosis or dermatitis herpetiformis
Cheilosis and glossitis
Evidence of peripheral neuropathy
Chvostek sign or Trousseau sign
Malignant diseases are more frequent in
patients with long-term untreated classical CD.
Small-bowel adenocarcinoma, esophageal and
oropharyngeal squamous-cell carcinoma, and
non-Hodgkin’s lymphoma occur more often in
CD patients than in healthy control
Measurement of bone mineral density is
recommended when CD has been diagnosed,
as reduced bone density is common in both
adults and children with CD. The reduction in
bone density is more severe in symptomatic
CD than in the silent form and is associated
with an increased risk of fracture.
Autoimmune disorders occur ten times more
frequently in adult patients with celiac disease
than in the general population.
Such disorders include:
• Insulin-dependent type 1 diabetes
• Thyroid disease
• Sjögren’s syndrome
• Addison’s disease
• Autoimmune liver disease
• Neurological disorders
Dermatitis herpetiformis is considered to be a
cutaneous manifestation of gluten sensitivity in
patients with CD. Dermatitis herpetiformis
(DH) is a severe, itchy, blistering skin disease.
The rash usually occurs on the elbows, knees,
and buttocks. Although people with DH do not
usually have digestive-tract symptoms, they
usually have the intestinal damage
characteristic of CD.
Lactose intolerance is the inability to break down
a type of natural sugar called lactose.
Lactose is commonly found in dairy products,
such as milk and yogurt.
A person becomes lactose intolerant when his or
her small intestine stops making enough of the
enzyme lactase to digest and break down the
When this happens, the undigested lactose
moves into the large intestine. The bacteria that
are normally present in the large intestine
interacts with the undigested lactose. The
condition may also be called lactase deficiency.
Lactose, a disaccharide, is present in milk and processed
foods. Dietary lactose must be hydrolyzed to a
monosaccharide in order to be absorbed by the small
intestinal mucosa. A deficiency of intestinal lactase
prevents hydrolysis of ingested lactose. The osmotic
load of the unabsorbed lactose causes secretion of fluid
and electrolytes until osmotic equilibrium is reached.
Dilation of the intestine caused by the osmosis induces
an acceleration of small intestinal transit, which
increases the degree of maldigestion. Within the large
intestine, free lactose is fermented by colonic bacteria to
yield short-chain fatty acids and hydrogen gas. The
combined increase in fecal water, intestinal transit, and
generated hydrogen gas accounts for the wide range of
There are three main types of lactose intolerance,
each with different causes:
Primary Lactose Intolerance
Secondary Lactose Intolerance
Congenital or Developmental Lactose
This is the most common type of lactose intolerance.
Most people are born with enough lactase. Babies need
the enzyme in order to digest their mother’s milk.
However, the amount of lactase a person makes may
decrease over time. This is because as people age, they
eat a more diverse diet and rely less on milk.
The decline in lactase is gradual. This type of lactose
intolerance is more common in people with Asian,
African, Native American, or Mediterranean ancestry.
Intestinal diseases such as celiac disease and
inflammatory bowel disease or a surgery or
injury to your small intestine can also cause
lactose intolerance. Lactase levels may be
restored if the underlying disorder is treated
In very rare cases, lactose intolerance is
inherited. A defective gene can be passed from
the parents to a child, resulting in the complete
absence of lactase in the child. This is referred
to as congenital lactose intolerance.
The baby will be intolerant of his or her
mother’s milk. He or she will have diarrhea as
soon as human milk or a formula containing
lactose is introduced. If it is not recognized and
treated early on, the condition can be life
Occasionally, a type of lactose intolerance
called developmental lactose intolerance occurs
when a baby is born prematurely. This is
because lactase production in the fetus begins
later in the pregnancy, after at least 34 weeks.
Primary lactase deficiency - 70% of the world's
population. Prevalence varies with ethnicity - eg,
2% in Northern Europeans and up to 80% in
Age of presentation also varies - eg, Hispanic,
Asian and Afro-Caribbean children present before
the age of 5 years, whereas Northern Europeans
usually present after the age of 5.
Lactose intolerance in adults is very common and
lactose may be found in many unexpected sources.
These include saccharine processed meats, bread,
cake mixes, soft drinks, and lagers. This may
account for unexplained symptoms, including
some cases of irritable bowel disease.
Congenital lactose intolerance is inherited as an
autosomal recessive trait and is very rare.
Primary lactose intolerance is due to low levels of
lactase, which develop after childhood.
Secondary, or acquired, lactase deficiency may develop in a person
with a healthy small intestine during episodes of acute illness. This
occurs because of mucosal damage or from medications. Some
causes of secondary lactase deficiency are as follows:
Symptoms are caused only by the ingestion of
lactose, found in milk and other dairy
products. They are affected by the amount of
lactose ingested and how fast the small
intestine is presented with the lactose load.
They will be more marked if the lactose reaches
the intestinal mucosa fast but less so if gastric
emptying is delayed as by being ingested with
a large meal. Degree of symptoms is also
affected by individual sensitivity and colonic
Symptoms result from reduced absorption of
lactose which is then broken down by intestinal
bacteria leading to gas and short-chain fatty
Gas build up causes:
The acidic and osmotic effects of undigested
lactose may cause:
Loose watery stool - with a degree of urgency an
hour or two after ingestion of milk.
Perianal itching due to acidic stools.
Symptoms occur from one to several hours after
ingestion of milk or dairy products. These
symptoms are very nonspecific and occur with
other disorders such as milk-protein sensitivity,
allergic-type reactions to other substances in the
meal, or intolerance of other saccharides.
Whipple's disease is a rare bacterial infection
that most often affects your gastrointestinal
system. Whipple's disease interferes with
normal digestion by impairing the breakdown
of foods, such as fats and carbohydrates, and
hampering your body's ability to absorb
Whipple's disease also can infect other organs,
including your brain, heart, joints and eyes.
The cause of Whipple's disease is infection with
the bacterium Tropheryma whipplei.
This bacterium initially affects the mucosal
lining of your small intestine, forming small
lesions within the intestinal wall. The
bacterium also damages the fine, hair-like
projections (villi) that line the small intestine.
With time, the infection can spread to other
parts of your body.
The bacteria will lead to the development of
internal sores and cause body tissue to thicken.
When the villi (finger-like tissues that absorb
nutrients in the small intestine) begin to
thicken, their natural shape begins to change.
This damages the villi and prevents them from
effectively absorbing nutrients. This, in turn,
leads to many of the symptoms connected with
Whipple's Disease: showing macrophages in the
Because so little is known about the bacterium that
causes Whipple's disease, risk factors for the disease
haven't been clearly identified. Based on available
reports, it appears more likely to affect:
Middle-age and older individuals.
Males more than females.
Family clusters (suggesting an immunogenetic
HLA-B27 antigen; HLA-DRB1*13 and DQB1*06
Sewage plant workers, farmers and agricultural
Because it causes your body to be unable to
properly absorb nutrients, Whipple’s disease
affects many different parts of the body and is
associated with a variety of symptoms.
In advanced disease, the infection may spread
from the intestines to other organs such as the
heart, lungs, brain, joints, and eyes.
Gastrointestinal signs and symptoms are
common in Whipple's disease and may
Abdominal cramping and pain, which may
worsen after meals
Weight loss, associated with the malabsorption
Other frequent signs and symptoms associated
with Whipple's disease include:
Inflamed joints, particularly your ankles, knees
In some cases, signs and symptoms of
Whipple's disease may include:
Enlarged lymph nodes
Skin darkening (hyperpigmentation) in areas
exposed to the sun and in scars
Neurological signs and symptoms may include:
Visual impairment, including lack of control of
The lining of your small intestine has fine, hair-like
projections (villi) that help your body absorb
nutrients. Whipple's disease damages the villi,
impairing nutrient absorption. Nutritional
deficiencies are common in people with Whipple's
disease and can lead to fatigue, weakness, weight
loss and joint pain.
Whipple's disease is a progressive and potentially
fatal disease. Although the infection is rare,
associated deaths continue to be reported, due in
large part to late diagnoses and delayed treatment.
Death often is caused by the spread of the infection
to the central nervous system, which can cause
Tropical sprue is caused by inflammation of your
intestines. This swelling makes it more difficult for
you to absorb nutrients from food.
People with tropical sprue do not absorb nutrients
properly, especially vitamin B12 and folic acid.
Normal small intestines have fingerlike projections
called villi that provide more surface area for
nutrients to be absorbed. In people with tropical
sprue, these villi are flattened, making absorption
The exact role of microbial agents in the
initiation and propagation of the disease is
poorly understood. One theory is that an acute
intestinal infection leads to jejunal and ileal
mucosa injury; then intestinal bacterial
overgrowth and increased plasma
enteroglucagon results in retardation of small-
intestinal transit. Central to this process is
folate deficiency, which probably contributes to
further mucosal injury.
Hormone enteroglucagon and motilin levels are
elevated in patients with tropical sprue. Enterocyte
injury can cause these elevations. Enteroglucagon
causes intestinal stasis, but the role of motilin is not
The upper small intestine is predominantly
affected; however, because it is a progressive and
contiguous disease, the distal small intestine up to
the terminal ileum may be involved. Pathological
changes are rarely demonstrated in the stomach
and colon. Coliform bacteria, such as Klebsiella, E
coli and Enterobacter species are isolated and are the
usual organisms associated with tropical sprue.
Tropical sprue is rare unless you live in or visit
Researchers believe the condition is caused by an
overgrowth of bacteria in your intestines. The
specific bacteria that cause tropical sprue are
You may be at risk for tropical sprue if you:
live in a tropical area
have traveled through a tropical area for a long
period of time
Tropical sprue usually occurs in residents of
tropical or subtropical, usually in developing
The incidence varies considerably with geography.
It occurs mostly in South East Asia and the
There is no predilection for race or gender.
It tends to affect adults but can also occur in
The condition may present in natives or travellers
and may not present until after they have left the
Symptoms of tropical sprue may include any of the
diarrhea, which may get worse on a high-fat diet
Short bowel syndrome is a complication that can
occur in people who have a large part or all of their
small intestine removed.
Short bowel syndrome (SBS), a disorder
characterized by diarrhea, malabsorption, fluid and
electrolyte disturbances, and eventually
Short bowel syndrome may be present at birth due
to a congenital anomaly or may develop in older
infants and children as a result of disease or trauma,
occurring later in life.
Short bowel syndrome may be a congenital or
acquired condition. Infants may be born with congenital
jejunal or ileal atresia.
Otherwise, short bowel syndrome results from surgical
resection of bowel. This is usually related to multiple
resections for recurrent Crohn’s disease, massive
enterectomy made necessary because of a
catastrophic vascular event such as mesenteric arterial
embolism, venous thrombosis, volvulus, trauma, or tumor
resection in adults, and, in children, gastroschisis,
necrotizing enterocolitis (NEC), and volvulus.
Factors that may increase your risk of short
bowel syndrome include:
Crohn's disease, which is the most common
reason for the removal of the small intestine
Premature birth or very low birth weight
Symptoms of short bowel syndrome may include:
Inflammatory Bowel Diseases (IBD) is a broad
term that describes conditions with chronic or
recurring immune response and inflammation
of the gastrointestinal tract. The two most
common inflammatory bowel diseases are
ulcerative colitis and Crohn’s disease.
Both illnesses have one strong feature in common.
They are marked by an abnormal response by the
body’s immune system.
Normally, the immune cells protect the body from
infection. In people with IBD, however, the
immune system mistakes food, bacteria, and other
materials in the intestine for foreign substances
and it attacks the cells of the intestines.
In the process, the body sends white blood cells
into the lining of the intestines where they produce
chronic inflammation. When this happens, the
patient experiences the symptoms of IBD.
Symptoms (Intestinal) include:
Diarrhea: Possible presence of mucus/blood in stool;
occurs at night
Constipation: May be the primary symptom in UC and
limited to rectum; obstipation may occur; may proceed
to bowel obstruction
Bowel movement abnormalities: Possible presence of
pain or rectal bleeding, severe urgency, tenesmus
Abdominal cramping and pain: Commonly present in
the right lower quadrant in CD.
Nausea and vomiting: More often in CD than in UC
Systemic symptoms include:
Irregular bowel habits, passage of mucus without
blood or pus
Grossly bloody stools
Perianal disease (e.g., fistulas, abscesses)
In several studies, genetic factors appeared to
influence the risk of inflammatory bowel
disease (IBD) by causing a disruption of
epithelial barrier integrity, deficits in
autophagy,deficiencies in innate pattern
recognition receptors, and problems with
The immune response disrupts the intestinal
mucosa and leads to a chronic inflammatory
Three characteristics define the etiology of
inflammatory bowel disease (IBD):
An altered, dysregulated immune response;
An altered response to gut microorganisms.
The peak age of onset for IBD is 15 to 30 years old,
although it may occur at any age. About 10% of
cases occur in individuals younger than 18 years.
Ulcerative colitis is slightly more common in
males, whereas Crohn’s disease is marginally more
frequent in women.
IBD occurs more in people of Caucasian and
Ashkenazic Jewish origin than in other racial and
IBD can be associated with several
gastrointestinal complications, including risk of
hemorrhage, perforation, strictures, and
fistulas—as well as perianal disease and related
complications, such as perianal or pelvic
abscesses, toxic megacolon, and malignancy
(colorectal cancer, cholangiocarcinoma).
Extra intestinal complications
Extra intestinal complications include :
Ulcerative colitis is an inflammatory bowel
disease (IBD) that causes long-lasting
inflammation in part of your digestive tract.
ulcerative colitis can be debilitating and
sometimes can lead to life-threatening
complications. Because ulcerative colitis is a
chronic condition, symptoms usually develop
over time, rather than suddenly.
Ulcerative colitis usually affects only the
innermost lining of your large intestine (colon)
and rectum. It occurs only through continuous
stretches of your colon, unlike Crohn's disease,
which occurs anywhere in the digestive tract
and often spreads deeply into the affected
There's no known cure for ulcerative colitis, but
therapies are available that may dramatically
reduce the signs and symptoms of ulcerative
Ulcerative colitis symptoms can vary,
depending on the severity of inflammation and
where it occurs. For these reasons, doctors
often classify ulcerative colitis according to its
Here are the signs and symptoms that may
accompany ulcerative colitis, depending on its
Ulcerative proctitis. In this form of ulcerative
colitis, inflammation is confined to the area
closest to the anus (rectum), and for some
people, rectal bleeding may be the only sign of
the disease. Others may have rectal pain and a
feeling of urgency. This form of ulcerative
colitis tends to be the mildest.
Proctosigmoiditis. This form involves the
rectum and the lower end of the colon, known
as the sigmoid colon. Bloody diarrhea,
abdominal cramps and pain, and an inability to
move the bowels in spite of the urge to do so
(tenesmus) are common problems associated
with this form of the disease.
Left-sided colitis. As the name suggests,
inflammation extends from the rectum up
through the sigmoid and descending colon,
which are located in the upper left part of the
abdomen. Signs and symptoms include bloody
diarrhea, abdominal cramping and pain on the
left side, and unintended weight loss.
Pancolitis. Affecting more than the left colon
and often the entire colon, pancolitis causes
bouts of bloody diarrhea that may be severe,
abdominal cramps and pain, fatigue, and
significant weight loss.
Fulminant colitis. This rare, life-threatening
form of colitis affects the entire colon and
causes severe pain, profuse diarrhea and,
sometimes, dehydration and shock. People
with fulminant colitis are at risk of serious
complications, including colon rupture and
toxic megacolon, a condition that causes the
colon to rapidly expand.
Inflammation begins in the rectum and extends
proximally in an uninterrupted fashion to the
proximal colon and could eventually involve the
entire length of the large intestine.
The rectum is always involved in ulcerative colitis;
and unlike in Crohn disease, there are no "skip
Even with less than total colonic involvement, the
disease is strikingly and uniformly continuous. As
ulcerative colitis becomes chronic, the colon
becomes a rigid foreshortened tube, leading to the
No one is quite sure what triggers ulcerative
colitis, but there's a consensus as to what
doesn't. Researchers no longer believe that
stress is the main cause, although stress can
often aggravate symptoms. Instead, current
thinking focuses on the following possibilities:
Immune system. Some scientists think a virus or
bacterium may trigger ulcerative colitis. The
digestive tract becomes inflamed when your
immune system tries to fight off the invading
microorganism (pathogen). It's also possible that
inflammation may stem from an autoimmune
reaction in which your body mounts an immune
response even though no pathogen is present.
Heredity. Because you're more likely to develop
ulcerative colitis if you have a parent or sibling
with the disease, scientists suspect that genetic
makeup may play a contributing role. However,
most people who have ulcerative colitis don't have
a family history of this disorder.
Ulcerative colitis affects about the same number of women
and men. Risk factors may include:
Age. Ulcerative colitis usually begins before the age of 30.
But, it can occur at any age, and some people may not
develop the disease until their 50s or 60s.
Race or ethnicity. Although whites have the highest risk
of the disease, it can occur in any race. If you're of
Ashkenazi Jewish descent, your risk is even higher.
Family history. You're at higher risk if you have a close
relative, such as a parent, sibling or child, with the
Possible complications of ulcerative colitis include:
A hole in the colon (perforated colon)
Liver disease (rare)
Inflammation of your skin, joints and eyes
An increased risk of colon cancer
A rapidly swelling colon (toxic megacolon)
Crohn’s disease is a condition of chronic
inflammation potentially involving any
location of the gastrointestinal tract, but it
frequently affects the end of the small bowel
and the beginning of the large bowel.
Loss of appetite
However, the disease is not always limited to the
gastrointestinal tract; it can also affect the joints, eyes,
skin, and liver.
Crohn disease can affect any portion of the
gastrointestinal tract, from the mouth to the anus,
and causes 3 patterns of involvement:
inflammatory disease, strictures, and fistulas.
The most important pathologic feature of Crohn
disease is that it is transmural, involving all layers
of the bowel, not just the mucosa and the
submucosa, which is characteristic of ulcerative
Furthermore, Crohn disease is discontinuous, with
skip areas interspersed between 2 or more
Late in the disease, the mucosa develops a
cobblestone appearance, which results from
deep, longitudinal ulcerations interlaced with
intervening normal mucosa .
Rectal sparing is a typical but not constant
feature of Crohn disease. However, anorectal
complications (e.g., fistulas, abscesses) are
Much less commonly, Crohn disease involves
the more proximal parts of the GI tract,
including the mouth, tongue, esophagus,
stomach, and duodenum.
The most common complication of Crohn’s
disease is blockage of the intestine due to
swelling and scar tissue.
Symptoms of blockage include cramping pain,
vomiting, and bloating.
Another complication is sores or ulcers within
the intestinal tract. Sometimes these deep ulcers
turn into tracts—called fistulas.
Patients may also develop a shortage of proteins,
calories, or vitamins.
The incidence of gallstones and kidney stones is increased in
Crohn disease because of malabsorption of fat and bile salts.
Gallstones are formed because of increased cholesterol
concentration in the bile, which is caused by a reduced bile
Patients who have Crohn disease with ileal disease or
resection are also likely to form calcium oxalate kidney stones.
With the fat malabsorption, unabsorbed long-chain fatty acids
bind calcium in the lumen. Oxalate in the lumen is normally
bound to calcium. Calcium oxalate is poorly soluble and
poorly absorbed; however, if calcium is bound to
malabsorbed fatty acids, oxalate combines with sodium to
form sodium oxalate, which is soluble and is absorbed in the