This document discusses the evaluation and management of chronic diarrhea and malabsorption syndrome. It begins with an introduction to chronic diarrhea and outlines the pathophysiology, including osmotic, secretory, inflammatory, and motility disorders. Common causes are then reviewed including infections, malignancies, celiac disease, tropical sprue, and short bowel syndrome. Management involves fluid/electrolyte replacement, treating the underlying cause, and symptomatic relief. Malabsorption syndrome and its specific etiologies like celiac disease, Whipple's disease, and tropical sprue are also summarized. The document stresses the importance of a thorough clinical evaluation to identify the cause and guide appropriate investigations and therapy.

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EVALUATION OF CHRONIC
DIARRHOEA AND
MALABSORPTION SYNDROME
DR C.A ONYEKWERE
(MD, FMCP, FACP, AGAF, FASGE)
PROFESSOR/CONSULTANT PHYSICIAN
& GASTROENTEROLOGIST
LASUCOM/LASUTH,IKEJA.

2. Outline
◼ Introduction
◼ Pathophysiology
◼ Causes of chronic diarrhoea
◼ Management of chronic diarrhoea
◼ Malabsorption syndromes
◼ Summary
◼ Appreciation
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3. 01/08/2022 3
Introduction
According to the 2013 WGO systematic review
which was updated in 2016, abnormal stool
form and not frequency defines Diarrhoea.
This may be ass. With abdominal pain, tenesmus
or change in frequency.
It is said to be chronic when it persists for more
than four weeks.

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REVIEW OF PHYSIOLOGY
Approximate volumes of fluid
secreted into and reabsorbed from
the intestine of an adult.
Source of
fluid
Vol.enteri
ng
Site of
absorptio
n
Vol.reabs
orbed
Efficiency
Diet 2 litres jejunum 4-5/9
litres
50%
Saliva 1 litre ileum 3-4/4-5
litres
75%
Gastric 2 litres Colon 90%
Bile 1 litre
Pancreatic 2 litres
Small 1 litre

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PATHOPHYSIOLOGY
Osmotic Diarrhoea – The gut acts as a semi-permeable
membrane and fluid enters the bowel to an area of high solute
concentration.e.g Magnesium or other unabsorbable ingested
substance.
Secretory Diarrhoea – There is a disruption of the basal secretion
of CL- into the lumen normally maintained by an integrated
paracrine, autocrine, luminal and endocrine modulation as in
cholera.
Inflammatory or Exudative Diarrhoea– This occurs ‘cos of damage
to the` intestinal mucosa leading to exudation of fluid and blood
into the lumen.
Motility Disorder – DM, Hyperthyroidism,Post-vagotomy diarrhoea,
carcinoid syndrome are all due to abnormal motility.
Combined mechanism.

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CAUSES OF CHRONIC DIARRHOEA
CONGENITAL –
Lactase deficiency
ACQUIRED –
Infections– Viral(HIV-enteropathy or in assoc. with cryptosporidium,microsporidium
or isospora belli)
-- Bacterial-salmonella, shigella, Pseudomemb colitis
Mycob TB
-- Parasitic-E histol, strongyloidiasis
-- Fungal-Histoplasma
-- Inflammatory – Ulcerative colitis
-- Crohns dx
-- Coeliac dx
-- Tropical sprue
- Microscopic colitis
Neoplasia – CA Colon
Malabsorption syndrome
Functional bowel disorder-IBS-D, functional diarrhea
Endocrine – Thyrotoxicosis
-- DM

7. Common causes locally
◼ The causes of chronic diarrhoea varies in different
geographical setting; in the developed world,
infective causes are rare unlike the situation locally;
common causes here include
◼ HIV related
◼ Intestinal amebiasis
◼ Tuberculosis
◼ Diarrhoea predominant IBS
◼ DM
◼ Unidentified (Non-specific microscopic colitis)-often
thought to be drug induced (NSAIDS,PPI
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8. HIV/AIDs and diarrhoeal diseases-
◼ Diarrheal disease in HIV-infected patients is
frequently caused by infectious agents but may
also be due to infiltrative diseases, malignancies
and drugs.
◼ The infectious pathogens associated with
diarrheal disease in HIV infection may vary with
the degree of immunocompromise in the host

9. Infective agents in HIV associated
diarrhoea and site of action
Pathogen Small bowel Colon
Bacteria
Salmonella*
Escherichia coli•
Clostridium perfringens
Staphylococcus aureus
Aeromonas hydrophila
Bacillus cereus
Vibrio cholera
Campylobacter*
Shigella
Clostridium difficile
Yersinia
Vibrio parahaemolyticus
Enteroinvasive E. coli
Plesiomonas shigelloides
Klebsiella oxytoca(rare)
Virus
Rotovirus
Norovirus
Cytomegalovirus*
Adenovirus
Herpes simplex virus
Protozoa
Cryptosporidium*
Microsporidium*
Isospora
Cyclospora
Giardia lamblia
Entamoeba histolytica

10. HIV enteropathy:
•
• HIV enteropathy is an idiopathic form of diarrhea that can
occur during the acute phase of HIV infection through
advanced AIDS and for which there is no identified pathogen.
• Histologically, villous atrophy, crypt hyperplasia and villous
blunting, inflammatory infiltrates of lymphocytes in the lamina
propria, exemplify damage to the GI tract.
• HIV enteropathy may improve with HAART but may also occur
in patients on HAART.
• The pathogenic mechanisms leading to HIV enteropathy
remain unclear but may involve effects of HIV infection on the
GI tract and the gut-associated lymphoid tissue

11. HAART- associated diarrhea
• Diarrhea may be associated with many of the therapies
used (HAART regimens.)
• In an analysis of clinical trials using consistent reporting, up
to 19% of patients treated with HAART reported moderate
to potentially life-threatening diarrhea that was considered
related to the drug (Hill,2009).
• Of particular issue is the PI ritonavir.
• HAART-associated diarrhea may be caused by a variety of
mechanisms including increased calcium-dependent
chloride conductance and cellular apoptosis, necrosis and
decreased proliferation of intestinal epithelial cells.
•

12. GI Malignancies in HIV
associated diarrhea:
◼
◼ GI malignancies like Kaposi sarcoma and
lymphomas are associated with diarrhea in HIV-
infected patients.
◼

13. IBS-diarrhea type & functional
diarrhea
◼ Defined by Rome IV criteria; emphasizes recurrent
abdominal pain associated with change in stool
form (diarrhea >25% of the time and
constipation<25% of the time) in the absence of
alarm features.
◼ In functional diarrhea there is absence of pain.
◼ Microscopic colitis can present like above but for
presence of alarm features sometimes and
symptoms are often more severe
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MANAGEMENT
AIM – Fluid and electrolyte replacement
-To ascertain the cause –intestinal (small or large
bowel) or extra intestinal
-- To treat the cause
To determine the cause – a careful clinical assessment will guide
use of different investigative modality some of which may not
apply to a particular patient
Hx – Purgative abuse, prior antibiotic, NSAID use, nature of
stool– presence of blood, mucus, watery stool or steatorrhea.
Presence and location of any abdominal pain or tenesmus.
Physical exam for evidence of weight loss, nutritional deficiency,
tenderness and findings on rectal examination as well as
features indicative of specific aetiology

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Investigative modalities
Clinical evaluation
◼ Blood count, ESR, C-reactive protein
◼ Retroviral screening
◼ Stool analysis and culture
◼ Stool calprotectin level
◼ Sigmoidoscopy/Colonoscopy
◼ Small bowel radiology
◼ Other tests –Jejunal aspirate analysis, Jejunal
biopsy, Breath test, Manteaux tests, TFT, CXR
◼ Motility studies

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TREATMENT
FLUID AND ELECTROLYTE
REPLACEMENT
ANTIMOTILITY AGENTS
ANTIMICROBIALS
TREAT SPECIFIC CAUSE—DM
?PROBIOTICS (lactobacillus,
saccharomyces)

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Unidentified cause
◼ Symptomatic treatment
◼ Regular follow-up with repeated sigmoidoscopy
and biopsy till diagnosis is established

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Malabsorption syndrome
◼ Refers to a situation where there is impaired
absorption of one or more nutrients from the
G.I.T

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Causes of malabsorption syndrome
◼ Chronic pancreatic damage: alcohol excess,
gallstones,autoimmune,hypertriglyceridaemia.
◼ Chronic hepatobiliary disorders
◼ Intestinal causes

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Intestinal causes
◼ Mucosal- Coeliac, Tropical sprue, whipples dse.,
Parasites e.g. Giardiasis, Drugs e.g. cholestyramine,
Lactase deficiency, Dermatitis herpetiformis.
◼ Structural-Crohns, Int resection, bye-pass , stricture,
diverticula, fistula, blind loop, Post irradiation, Int. TB,
Amyloidosis, Lymphoma, Mesenteric arterial
insufficiency.
◼ Motility disorder-systemic sclerosis, DM,
Thyrotoxicosis, Carcinoid syndrome

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Clinical presentation
◼ Diarrhoea-steartorrhoea
◼ Abdominal symptoms & signs
◼ Nutritional deficiencies-isolated anemia ( Fe, Folic
acid,B12),bleeding(vit K) Rickets (vit. D),or multiple,
Weight loss, increased predisposition to infection due low
plasma proteins.
◼ General ill health
◼ Features of causative illness e.g Crohns.

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Investigation
◼ Document malabsorption- Diarrhea, weight loss abnormal
tests(FBC, INR, presence of fat globules, pancreatic
elastase in stool using Elisa)
◼ Identify Site-jejunal biopsy (distal duodenal biopsy) for
mucosal lesions
◼ Small bowel radiology(small bowel enema better than follow
through) for Structural causes.
◼ Aspiration of jejunal juice may detect G lamblia and bacterial
overgrowth
◼ Defective luminal digestion could be confirmed by lactose
breath test or mucosal enzyme assay.
◼ Pancreatic lesion employing Imaging (USS, CT) though
EUS is gold standard
◼ Assess severity- BMI, Laboratory evidence of malabsorption
nutritional assessment

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Specific malabsorption syndromes
◼ Coeliac disease
◼ Crohns disease
◼ Tropical sprue
◼ Giardiasis
◼ Small intestinal Bacterial overgrowth
◼ Bile acid malabsorption
◼ Hypolactasia (lactase deficiency)
◼ Short bowel syndrome
◼ Whipples disease

24. Celiac disease.
◼ is an immune reaction to eating gluten, a
protein found in wheat, barley and rye. Over
time, this reaction produces inflammation that
damages the small intestine's lining and
prevents absorption of some nutrients
(malabsorption). Is underdiagnosed or
misdiagnosed due to overlap of
symptomatology with other disorders.
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25. Celiac disease contd
◼ High levels of anti-tissue transglutaminase
antibodies (tTGA) or anti-endomysium antibodies
(EMA). A biopsy of the small intestine (usually
distal duodenal biopsy) is performed to confirm the
diagnosis No cure for celiac disease — but
following a strict gluten-free diet can help manage
symptoms and promote intestinal healing
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26. Whipples disease
◼ Caused by Tropheryma whipplei bacteria
belonging to actinomycetes; affects the GIT but
can spread to the heart, lungs, brain, joints and
eyes. Typically affects middle aged men and
responds to prolonged antibiotic therapy with
penicillin. Treatment can go on for upto 1 year.
If untreated usually fatal
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27. Tropical sprue
◼ a syndrome characterized by acute or chronic
diarrhea, weight loss, and malabsorption of
nutrients. It occurs in residents of or visitors to
the tropics and subtropics
◼ it may not appear until as long as 10 years after
the patient has left there.
◼ The exact causative factor of tropical sprue is
unknown, but an intestinal microbial infection is
believed to be the initiating insult
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28. Tropical sprue contd.
◼ 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
◼ 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
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29. Short Bowel syndrome
◼ Short-bowel syndrome is a disorder clinically
defined by malabsorption, fluid and electrolyte
disturbances, and malnutrition
◼ The final common etiologic factor in all causes of
short-bowel syndrome is the functional or anatomic
loss of extensive segments of small intestine so
that absorptive capacity is severely compromised
◼ The management involves the establishment of
central venous access for delivery of total
parenteral nutrition (TPN), intestinal
transplantation,
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30. Summary
◼ Chronic diarhoea including malabsorption
syndrome remains an important clinical scenerio
which is often a diagnostic challenge to the
clinician and a cause of great morbidity and
sometimes mortality. It has a negative impact on
the patients quality of life and contributes to
absteeism and loss of man hours and of great
healthcare cost from numerous investigations
◼ A careful clinical evaluation bearing in mind the
underlying pathophysiology will guide choice of
investigations to arrive at the actual etiology and
subsequent appropriate therapy
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31. Appreciation
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