BSG Guidelines for the Investigation of Chronis Diarrhoea

1
BSG Guidelines (2003) for the Investigation of
Chronic Diarrhoea
2
Definition

• Chronic diarrhoea may be defined as the abnormal
  passage of three or more loose or liquid stools
  per day for more than four weeks and/or a daily
  stool weight greater than 200 g/day.

3
Prevalence

• Talley et al reported a prevalence of chronic
  diarrhoea of between 7 and 14 in an elderly
  population
• estimates of the prevalence of chronic diarrhoea
  in a Western population are of the order of 45

4
Algorithm for investigation of chronic diarrhoea
5
Causes of chronic diarrhoea

• Other small bowel enteropathies (for example,
  Whipples disease,
• tropical sprue, amyloid, intestinal
  lymphangiectasia)
• Bile acid malabsorption
• Disaccharidase deficiency
• Small bowel bacterial overgrowth
• Mesenteric ischaemia
• Radiation enteritis
• Lymphoma
• Giardiasis (and other chronic infection)

• Colonic
• Colonic neoplasia
• Ulcerative and Crohns colitis
• Microscopic colitis
• Small bowel
• Coeliac disease
• Crohns disease

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Causes of Chronic Diarhoea

• Other
• Factitious diarrhoea
• Surgical causes (e.g. small bowel resections,
  internal fistulae)
• Drugs
• Alcohol
• Autonomic neuropathy

• Pancreatic
• Chronic pancreatitis
• Pancreatic carcinoma
• Cystic fibrosis
• Endocrine
• Hyperthyroidism
• Diabetes
• Hypoparathyroidism
• Addisons disease
• Hormone secreting tumours (VIPoma, gastrinoma,
  carcinoid)

7
Initial investigations

• History and Examination
• Aim to establish
• (a) organic vs functional,
• (b) malabsorptive vs colonic/inflammatory forms
  of diarrhoea
• (c) to assess for specific causes of diarrhoea.

8
Symptoms of Organic Disease

• less than three months duration,
• Predominantly nocturnal or continuous (as opposed
  to intermittent) diarrhoea,
• significant weight loss.

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Functional Disease

• The absence of symptoms of organic disease, in
  conjunction with positive symptoms such as those
  defined in the Manning or Rome criteria and a
  normal physical examination, are suggestive of a
  functional bowel disturbance, but only with a
  specificity of approximately 5274.
• Unfortunately, these criteria do not reliably
  exclude inflammatory bowel disease.

10
Malabsorption Colonic/Inflammtory
steatorrhoea liquid loose stools with blood
bulky malodorous pale stools mucous discharge
Inspection of the stool may be helpful
in distinguishing these two
11
Risk Factors for Organic Disease

• Family history. Particularly of neoplastic,
  inflammatory bowel, or coeliac disease.
• Previous surgery.
• Previous Pancreatic disease
• Systemic disease i.e. Thyrotoxicosis/parathyroid
  disease
• Alcohol
• Drugs
• Recent overseas travel or other potential sources
  of infectious gastrointestinal pathogens
• Recent antibiotic therapy and Clostridium
  difficile infection
• Lactase deficiency

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Basic Investigations

• FBC
• U and Es
• liver function tests, including albumin
• vitamin B12 and folate,
• calcium, ferritin,
• ESR and CRP
• TFTs
• Coeliac screen- EMA (anti endomysial antibodies),
• Anti TTG (anti tissue tranglutaminase)

13
Stool Tests

• Inspection of stool
• Stool collection - 24-48hrs
• If less than 200g/day, no further investigations
  may be warranted
• Stool cultures
• Protozoan, giardasis and amoebiasis
• ELISA for giardiasis
• Stool osmolality limited use may help in
  differentiating secretory and osmotic diarrhoea

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Functional Disease

• Symptoms suggestive of Functional disease
• lt 45 years
• Normal basic investigations
• Diagnosis Irritable bowel syndrome

15
Factitious Diarrhoea

• a common cause of reported chronic diarrhoeal
  symptoms in Western populations.
• Due to
• laxative abuse
• adding of water or urine to stool specimens
• Up to 20 of patients that are seen in tertiary
  centres.
• Often underlying psychiatric hx such as eating
  disorders
• High index of suspicion

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Colonic/Terminal Ileal Disease

• Flexible Sigmoidoscopy
• Recommended in patients under 45 because covers
  most pathology in this age group
• Allows assessment and sampling of sigmoid and
  descending colon
• In a study (n809) of non HIV Non bloody chronic
  diarrhoea it was demonstrated that 15 of
  patients had colonic pathology
• 99.7 of these diagnoses could have been made
  from biopsies of the distal colon using a
  flexible sigmoidoscope,
• primary diagnoses being microscopic colitis,
  Crohns disease, melanosis coli, and ulcerative
  colitis.

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Colonic/Terminal Ileal Disease

• Colonoscopy
• Recommended in patients over 45 years old
• Diarrhoea may be caused by colorectal neoplasia
• One study showed prevalence of colonic neoplasms
  of 27 in those patients undergoing colonoscopy
  for a change in bowel habit
• 50 of neoplasms are proximal to splenic flexture
• Higher diagnostic yield with ileoscopy
  particularly in IBD
• preferred modality to exclude or confirm
  microscopic colitis
• Barium Enemas useful in complementing colonoscopy
  but has lower sensitivity in detecting neoplasms

18
Colonic/Terminal Ileal Disease

• If colonoscopy and barium enema negative
• Barium follow through further imaging of
  terminal ileum and proximal colon in patients
  with negative findings on colonoscopy and biopsy
• Enteroclysis/Technetium scan
• ?Superseded by CT with contrast and video
  endoscopy

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Malabsorption- Small Bowel

• Upper GI endoscopy with duodenal biopsies even in
  absence of EMA/TTG antibodies
• Small bowel imaging (barium follow through or
  enteroclysis) should be reserved for cases where
  small bowel malabsorption is suspected and distal
  duodenal histology is normal (C).

20
Malabsorption- Small Bowel

• If enteropathy (e.g. Whipples , tropical sprue
  amyloid)-
• Fat malabsorption
• faecal elastase and EMA is superior to 3 day
  stool samples for fat measurement.
• Breath tests 14C-triolein absorption to measure
  fat absorption in high faecal fat content

21
Malabsorption- Pancreatic

• Severe pancreatic insufficiency with
  malabsorption is normally associated with
  pancreatic duct abnormalities. ERCP offers the
  greatest sensitivity for the diagnosis of ductal
  changes- (however since the publication of this
  guideline in 2003 practice has changed as
  mentioned below MRCP has replaced ERCP as
  diagnostic option)
• MRCP has the potential to replace ERCP as the
  imaging modality of choice and has the advantage
  of avoiding the risks associated with ERCP

22
Malabsorption- Pancreatic

• Urine tests such as the Pancreolauryl test and
  stool tests such as faecal elastase or
  chymotrypsin poor sensitivity in mild/moderate
  pancreatic dysfunction
• Serum levels of pancreatic dysfunction are only
  affected in severe pancreatic dysfunction

23
Small bowel bacterial overgrowth

• Culture of small bowel aspirates is the most
  sensitive test for SBBO but methods are poorly
  standardised and positive results may not reflect
  clinically significant SBBO (B).
• Hydrogen breath tests have poor sensitivity but
  acceptable specificity, and are of value when a
  positive result is obtained.
• The glucose hydrogen breath test is recommended

24
Bile Acid Malabsorption

• Bile acid malabsorption (BAM) may occur when
  there isterminal ileal disease or resection.
  Measurement of serum 7a hydroxy-4-cholesten-3-one
  is an effective test for this but is seldom
  performed.
• 75Se homotaurocholate (75Se-HCAT) testing is more
  widely available and is a sensitive measure
• In the absence of these tests a therapeutic trial
  of cholestyramine is sometimes employed as a test
  for the presence of BAM, but the validity of this
  approach has not been subject to study

25
Hormone Secreting Tumours

• Diarrhoea due to hormone secreting tumours is
  extremely rare and
• testing for the presence of excess vasoactive
  intestinal peptide, gastrin, or glucagon in
  plasma is recommended only in the presence of
  high volume watery diarrhoea when other causes of
  diarrhoea have been excluded

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Summary

• History and examination extremely important
• Important to exclude functional diarrhoea with
  basic investigations and thorough history
• Coeliac serology tests should be done early in
  investigation
• In patients under the age of 45, flexible
  sigmoidoscopy is recommended
• In patients with one first degree relative with
  bowel neoplasm and above age of 45 warrant a
  colonoscopy

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Summary

• Obvious deficiencies in the investigation of
  SBBO, pancreatic insufficiency, BAM
• Empirical therapy is often employed

28

• Gut. 2003 July 52(Suppl 5) v1v15.Guidelines
  for the investigation of chronic diarrhoea, 2nd
  edition P Thomas, A Forbes, J Green, P Howdle, R
  Long, R Playford, M Sheridan, R Stevens, R
  Valori, J Walters, G Addison, P Hill, and G
  Brydon