This document discusses malabsorption syndromes and their evaluation. It begins by defining maldigestion and malabsorption. Common causes of malabsorption discussed include exocrine pancreatic insufficiency, bacterial overgrowth, and intestinal inflammation. A variety of tests are described to evaluate for fat, carbohydrate, protein and micronutrient malabsorption. These include fecal fat tests, D-xylose absorption tests, lactose breath tests, and Schilling tests. Endoscopy, imaging, and biopsy are also used in the diagnostic workup.

1. Candidate:-
Dr. Rohit Mehtani
RMO Medicine
M.Y. Hospital
Guide:-
Dr. Amit Agrawal
Assistant Professor
Dept. of Medicine
M.Y. Hospital

2.  Madigestion – impaired breakdown of nutrients to
absorbable products
 Malabsorption – defective mucosal uptake and
transport of adequately digested nutrients including
vitamins and trace elements.
 Most malabsorption syndromes are associated with
steatorrhoea – increase in stool fat excretion of >6% of
dietary fat intake.
 Malabsorption syndromes must be included in the
differentials of diarrhoea.

3.  Diarrhoea –
 Decrease in stool consistency, an increase in stool volume,
an increase in number of bowel movements, or any
combination of these three changes.
 Quantitative increase in stool water or weight > 200-225
mL or gram per 24 hour, when a western type diet is
consumed. Individuals consuming high fibre diet may
normally have a stool weight upto 400 g/24h.
 Secretory diarrhoea –
 Due to small and/or large intestinal fluid and electrolyte
secretion.
 Does not respond to prolonged fasting.
 Osmotic diarrhoea –
 Due to diminished absorption of one or more dietary
nutrients.
 Responds to prolonged fasting.

4.  HISTORY –
 Diarrohoea – duration, consistency, frequency, stool
characteristics, volume, association with diet, etc.
 Bloating, Abdominal pain
 Weight loss
 Weakness, bone pains
 Unexplained skin changes
 Mouth ulcers
 Previous abdominal surgery – partial/total gastrectomy, small
bowel resection, pancreas resection
 History of chronic pacreatitis
 Medications, Alcohol intake, history of radiotherapy
 Recurrent peptic ulcer disease
 Diabetes, CLD
 Family history – celiac disease, crohn’s disease, cystic fibrosis,
lactase deficiency
 Risk factors like HIV infection

7.  CBC & ESR
 S. Proteins, S. Albumin
 Electrolytes & RFT
 Calcium
 PT-INR
 Alkaline Phosphatase
 Cholesterol

8.  Take careful history including drug intake, travelling and
special foods, drinks or sweets
 Consider family history.
 Notice hints for malabsorption from physical
examination.
 Look at stool for volume, appearance, admixtures of
mucus, blood, parasites.
 Draw blood for screening laboratory examination to find
additional hints.

9. • H2 breath tests for carbohydrate malabsorption
• Anti-endomysial, anti-gliadin anti-ttg for celiac disease
• Search for giardia, enteropathogenic bacteria, parasites and ova
• Abdominal USG for gall bladder, liver, pancreas, intestinal wall aspects,
adenopathy, etc.
• Upper GI endoscopy including biopsy from stomach (?autoimmune gastritis ? H.
Pylori) and duodenum ( ?celiac disease, ?IBD)
• Colonoscopy and biopsy (?Vit. B12 deficiency, ?ileal disease, ?decreased bile salts)
If pancreatic
disease
suspected
• Test for secretory function – elastase or chymotripsin in stool
• CT, ERCP or MRCP
• Gold standard is secretin-pancreozymin test, but not routinely used.
If small
bowel
disease is
still
suspected
• Schilling-test (Vit B12)
• Glucose-H2-test (bacterial overgrowth)
• a1-antitrypsin clearance (intestinal protein loss)
• Small bowel X-ray (fistulae, diverticula, blind loops, short bowel, etc.)
• Angiography of celiac and mesenteric arteries (ischemic bowel damage)
If the case warrants further exploration go on with -

10. • Specific:
• Tests of fat absorption:
• Quantitative fecal fat estimation
Patient should be on daily diet containing 80-100
grams of fat.
Fecal fat estimated on 72 H collection.
6 grams or more of fat/day is abnormal.
• 14C-Triolein Test – it is a triglyceride which is hydrolysed by
pancreatic lipase. Absorption and metabolism of 14C – triolein
leads to increased excretion of 14CO2 by lungs.
• Sudan III test – qualitative test which detects clinically
significant steatorrhea in >90% cases
• NIRA (Near Infra Reflectance Assay) – equally accurate with
72 hours fecal fat estimation
• Allows simultaneous measurement of fecal fat, nitrogen,
carbohydrate

11.  SCHILLING TEST
 Patient is given oral dose of radiolabelled vitamin b-12
 One hour later, the patient is given i.m injection of
unlabelled vitamin B-12
 Patients urine is collected for a period of 24 hours
 Normally atleast 10% of the excreted Vitamin B-12 in
urine is radiolabelled

12. Carbohydrate absorption test
• D-xylose test – it is a pentose which is excreted
unchanged in urine.
• 25 g D-xylose is given and urine is collected for 5
hours.
• <4.5 g excretion reflects the presence of
duodenal/jejunal mucosal disease.
• It may also be abnormal in blind loop syndrome and
false positive in patients with large fluid collections in
third space, impaired renal functions, patients on ASA,
indomethacin, neomycin.
• In patients with fat malabsorption, this test differentiates
pancreatic from small intestinal malabsorpton. D-xylose
is normal in pancreatic disease.

13.  H2 breath test
 Baseline levels of hydrogen in breath are measured.
 Patient is given pure lactose (20 to 25 grams) and then hydrogen
levels in breath are measured every 15, 30 or 60 minutes for 2-3
hours.
 If the level of hydrogen rises above 20ppm above the preceeding
value within the test period, the test is positive.
 Lactose Tolerance test
 50 gram lactose given p.o
 Blood glucose is measured at 0, 60 and 120 minutes
 Blood glucose <20 mg/l along with development of symptoms is
characteristic of lactose intolerance
 Tests for bacterial overgrowth
 Quantitative bacterial count from aspirated small bowel
 <105/ml – jejunum
 >105/ml – ileum
 Enteral Protein loss is measured by measuring clearance of
alpha-1 antitrypsin
 Pancreatic insufficiency is tested by administering a meal of
hormonal secretagogues and then analysing duodenal fluid.

14. Radiographic Evaluation –
 Barium swallow and follow-through – to see Blind loop,
Stricture or J. diverticula.
A)Normal
B) Celiac Sprue
C)Jejunal Diverticulosis
D)Crohn’s Disease

15.  Primary indications are –
 evaluation of a patient with documented or suspected
steatorrhea or chronic diarrhoea.
 Diffuse or focal abnormalities of small intestine defined
on a small intestinal series.
 Lesions on small bowel biopsy may be –
 Diffuse, specific
 Patchy, specific
 Diffuse, nonspecific
 Identification of micro-organisms

18. A) Normal small
bowel mucosa
B) Celiac Sprue
C) Treated Celiac
Sprue
D) Intestinal
lymphangiectas
ia
E) Whipple’s
Disease
F) Intestinal
Lymphoma

19.  INADEQUATE DIGESTION
 Deficiency or inactivation of pancreatic lipase
 Exocrine pancreatic insufficiency – chronic pancreatitis, pancreatic
carcinoma, cystic fibrosis, congenital or acquired pancreatic insufficiency
 Gastrinoma – acid inactivation of lipase
 Drugs – orlistat
 IMPAIRED MICELLE FORMATION
 Liver disease
 Bacterial overgrowth in small intestine – anatomic stasis (blind
loop/fistula/stricture) or functional stasis
(diabetes/scleroderma/intestinal pseudo-ostruction)
 Interrupted enterohepatic circulation of bile salts – ileal resection,
crohn’s disease
 Drugs – Neomycin, cholestyramine, calcium carbonate
 Impaired mucosal absorption
 Intestinal resection or bypass
 Inflammation, infiltration or infection – crohn’s disease, amyloidosis,
scleroderma, lymphoma, eosinophilic enteritis, mastocytosis, tropical
sprue, celiac sprue, collagenous sprue, whipple’s disease, radiation
enteritis, folate and b12 deficiency, giardiasis, graft versus host disease
 Genetic disorders – disaccharidase deficiency, agammaglobulinemia,
abetalipoproteinemia, cystinuria, hartnup disease

20.  IMPAIRED NUTRIENT DELIVERY TO AND/OR FROM
INTESTINE
 Lymphatic disorders – lymphoma, lymphangiectasia
 Circulatory disorders – CHF, constrictive pericarditis,
vasculitis, mesentric artery atherosclerosis
 ENDOCRINE AND METABOLIC DISORDERS –
Diabetes, hyperthyroidism, hypoparathyroidism, adrenal
insufficiency, carcinoid syndrome.

22. Process Pathophysiologic
Defect
Disease Example
Synthesis Decreased Hepatic
Function
Cirrhosis
Biliary Secretion Altered canalicular
function
Primary biliary Cirrhosis
Maintainence of
Conjugated Bile acids
Bacterial overgrowth Jejunal diverticulosis
Reabsorption Abnormal ileal function Crohn’s Disease

23. Ileal dysfunction results in decrease in bile acid reabsorption and increase in
bile acid delivery to the large intestine which results in diarrhoea with or
without steatorrhea.
In patients with limited ileal disease often have diarrhoea due to active
chloride secretion in the colon because of bile acids, also known as choleretic
enteropathy.

24.  Dietary fat is composed exclusively of long chain triglycerides.
 Assimilation of dietary lipids has three phases –
 Intraluminal or digestive phase
 Mucosal or absorptive phase
 Delivery or postabsorptive phase

26.  Carbohydrates in diet are present in the form of starch,
disaccharide and glucose.
 They are absorbed only in small intestine and only in
the form of monosaccharides.
 Lactose malabsorption is the only clinically important
disorder and is due to lactase deficiency. It may be
primary or secondary –
 Primary Lactase deficiency – genetically determined decrease
or absence of lactase is noted.
 Secondary Lactase deficiency – seen in small intestinal
mucosal disease with abnormalities in both structure and
function of brush border enzymes and transport processes.
Ex:- Celiac disease.

27.  Mostly individuals with primary lactase deficiency are
asymptomatic.
 Few develop symptoms of lactose intolerance, like
diarrhoea, abdominal pain, cramps or flatus.

28.  Protein is present in diet as polypeptides and is
hydrolysed to dipeptides, tripeptides and amino acids
before absorption.
 Proteolysis occurs both in stomach and small intestine,
mediated by pepsinogen and trypsinogen.
 Protein digestion disorders are relatively rare. Three rare
genetic disorders are :-
 Enterokinase deficiency – due to absence of brush border
enzyme that converts trypsinogen to trypsin and is
associated with diarrhoea, growth retardation and
hypoproteinemia
 Hartnup Syndrome – defect in neutral amino acid
transport, characterised by pellagra like rash and
neuropsychiatric manifestations
 Cystinuria – defectin dibasic amino acid transport,
associated with renal calculi and chronic pancreatitis.