Download Chronic Diarrhoea

Chronic Diarrhoea
Dr Tien Huey Lim
Gastroenterologist
Middlemore Hospital &
MacMurray Gastroenterology
Chronic Diarrhoea- Definition
O Symptoms >4 weeks
O Passage of 3 or more loose or liquid stools
per day (or more frequent passage than is
normal for the individual) or daily stool
weight >200g/day
O Prevalance: 7-14% in western population
(Talley NJ, et al. Am J
Epidemiol1992;136:165–77)
Common causes
O Irritable bowel syndrome (IBS)
O Inflammatory bowel disease (IBD)
O Malabsorption
O Lactose intolerance
O Chronic pancreatitis
O Celiac disease
O Bacterial overgrowth of small intestine
O Bile salt diarrhoea
O Medication side effects
Chronic infections
O Clostridium difficile
O Aeromonas
O Giardia
O Cryptosporidium
O Consider in patients with specific risk factors
eg travel, HIV, antibiotic use, consumption of
potentially contaminated drinking water
Guidelines for investigation
O Aim: to maximise positive diagnoses whilst
minimising number and invasiveness of
investigations
O Low threshold for use of colonoscopy in
older subjects
O Less need for extensive investigations where
probability of benign disease is high eg
young patients with functional symptoms
O Good history is vital
O Symptoms that suggest organic bowel
disease:
O Diarrhoea within the last 3 months
O Nocturnal diarrhoea
O Continuous rather than intermittent
diarrhoea,
O Weight loss
Initial investigations
O Screening blood tests should include FBC, CRP,
U+E, LFTs, calcium, B12, folate, iron studies and
thyroid function. These have high specificity but
low sensitivity for presence of organic disease
(B).
O Although infectious diarrhoea is uncommon in
immunocompetent patients from the developed
world with chronic symptoms, stool for M+C+S
should be performed (C).
O Coeliac disease is the most common small
bowel enteropathy in Western populations.
Patients with diarrhoea should be screened
using serological tests (A).
O Factitious diarrhoea is common, and
screening for laxative abuse should be
performed early in the course of
investigation (B).
Guidelines (cont’d)…
O In patients <45 years with typical symptoms
of functional bowel disease, normal
examination and screening blood tests, a
positive diagnosis can be made with no
further investigations required (C).
O Patients <45 years with chronic diarrhoea
and/or atypical symptoms should undergo
flexible sigmoidoscopy in the first instance
as diagnostic yield differs little from
colonoscopy in this age group (B).
Guidelines (cont’d)
O In patients >45 years, colonoscopy is
preferred (B).
Pancreatic dysfunction
O Quantification of 3 day fecal fat is poorly
reproducible, unpleasant and non
diagnostic, and its use should be
discouraged (C).
O Newer specific tests of pancreatic
dysfunction, such as stool elastase, are
preferred (B) (sensitivity 63%, 100% and
100% for mild, moderate and severe
pancreatic insufficiency)
O Treatment = Creon tds with meals
Lactose intolerance
O Tests available in adults
O Hydrogen breath test
O Brush border enzyme levels (duodenal
biopsy)
O Practical test: glass of milk challenge +
lactase capsules
Bile acid malabsorption
O Occurs in 5-12% of patients post
cholecystectomy
O Also occurs post ileal resection
O 2* to excessive bile acids
O Treatment = cholestyramine
Tolerability of cholestyramine
Coeliac disease
O Coeliac serology should be done in all cases
O Anti-gliadin antibody test:
O Sensitivity: 75-95%
O Specificity: 80-95%
O Anti-endomysial antibody:
O Sensitivity: >90%
O Specificity >97%
O Transglutaminase antibody:
O Sensitivity: >90%
O Specificity >97%
• Beware IgA deficiency (1:200 prevalence)
Small bowel bacterial
overgrowth
O Bacterial concentrations in proximal jejunum
in normal healthy state <104 cfu/mL (colon
109 to 1012 cfu/mL)
O Risk factors: intestinal dysmotility 2* to
systemic disease eg diabetes, scleroderma,
intestinal pseudoobstruction; previous
surgery or strictures of small bowel, gastric
surgery, jejunal diverticulosis
Small bowel bacterial
overgrowth
O Gold standard = small bowel aspirate and
O
O
O
O
culture
Positive culture = >106 cfu/mL
Limited by lack of standardisation, sampling
errors, need for intubation
Breath tests available but poor sensitivity (60%)
and acceptable specificity (75%) (useful when
positive)
Empiric trial of antibiotics is an option
(ciprofloxacin/norfloxacin/cotrimoxazole)
Medications
O Responsible for up to 4% chronic diarrhoea
O Magnesium containing products
O NSAIDs
O Theophyllines
O Antibiotics
O Antineoplastic agents
O Metformin
O Antidepressants
Case 1
O 50 yr old man
O Approximately 7 year history loose bowels
5x/day
O Occasional nocturnal symptoms
O Mild discomfort before motions
O Systemically well
O No family history
O Managed with diastop prn at work
O Diarrhoea predominant IBS?
…possibly
O 80-90% will have a treatable underlying
cause
Diarrhoea predominant IBS
O Trial of low fibre diet
O No more than 3 pieces fruit/day
O No excess caffeine/ETOH
O No excess sorbital/fizzy drinks
O If fails, then consider other investigations depending
on age
O Trials of cholestyramine/antibiotics/creon
Case 2
O 40 year old female
O Gastroenteritis during overseas trip to
Thailand 4 months ago
O Ongoing loose motions and bloating, no
weight loss, no bleeding
O Bloods and stool NAD
Post infectious IBS
O Does it exist??
Post infectious IBS- The
Walkerton Experience
O Walkerton, Ontario, Canada
O May 2000: Heavy rains washed livestock fecal residue
from nearby farms into inadequately chlorinated
drinking water supplied from shallow well
O 2300 cases gastroenteritis
O E coli 0157, Campylobacter
O 27 cases of hemolytic uremic syndrome
O 8 deaths
O After 2 years follow up, prevalence of IBS 36% vs
10% in non infected controls (OR 4.8, p<0.001)
Post-infectious IBS
O Occurs 3-36% of patients after acute
gastroenteritis
O More likely with
O Increasing severity, duration>7 days,
bacterial etiology, female sex, pre-existing
depression/anxiety
Thought 2* to low grade ongoing inflammation,
increased intestinal permeability, altered gut
flora, altered gut motility
Post infectious IBS
O Treatment
O Reassurance (may need a normal test)
O Treat as per IBS subtype- often diarrhoea
predominant
O Hopefully will resolve with time
Other variations
O Post infectious visceral hypersensitivity
O Often requires pain team involvement
O Post infectious hyperemesis
O Young patients, ongoing vomitting post GI
infection
O Treat with long term PPI + Anti-emetics,
reassurance
O Very slow to resolve
Case 3
O 30 year old male
O 2 months diarrhoea 9-10x/day
O 7kg unintentional weight loss
O No family history of IBD
O Bloods normal apart from CRP of 9
Case 3
O Colonoscopy:
Case 3
O Started on pentasa, prednisone and
enemas
5-ASA in IBD
O Variety of formulations: Pentasa, Asacol,
Dipentum
O Meta-analysis of oral 5ASA for active UC
O 19 trials with 2032 patients, half placebo
controlled
O Mesalazine more than twice as effective as
placebo (OR 0.39: CI 0.29-0.52)
5-ASA in active Crohns
ileocolitis
O Meta-analysis of 3 placebo-controlled trials
O Pentasa 4g daily for 16 weeks x 615
patients
O Mean reduction of CDAI from baseline of -63
points, compared with 45 points for placebo
(p=0.04)
Maintaining remission
O All 5-ASA derivatives are effective for
maintaining remission in UC
O Less effective in maintaining remission in
Crohns
O Reduces relapse after surgery (NNT=8)
O Reduces the risk of colorectal cancer by up
to 75% (OR 0.25, CI 0.13 to 0.48)
Case 4
O 28 year old female
O Recent delivery of healthy baby girl 6
months ago
O 6 month history of outlet sounding PR
bleeding and variable bowel motions 15x/day
O Initial weight loss but now regained
O Family history of Crohns disease (mother)
Case 4
O Bloods: normal Hb but microcytosis
O Ferritin 16
O B12, folate, coeliac serology normal
O CRP 8
O Stool NAD
Case 4
O Fecal calprotectin 328 (<50)
O Colonoscopy:
Case 4
O Started on pentasa + azathioprine
O Now pregnant again with 2nd baby
Fecal calprotectin
O Protein released by WBC
O Found in inflamed areas of bowel
O Meta-analysis of 28 studies
O For distinguishing IBD and IBS in adults,
pooled sensitivity 93%, specificity 94% at
cut-off level 50ug/g
O Gray area = 50-150ug/g
O Used mostly for its negative predictive value
Waugh N, Health Technol Assess 2013; 17(55), 1-211.
Microscopic colitis
O Lymphocytic colitis and collagenous colitis
O Uncommon 5:100,000, increase with age
O No increased risk of colon cancer
O High false negative yield from rectosigmoid
histology (34-43%)(Offner 1999)
O Can co-exist with coeliac disease
Microscopic colitis
Microscopic colitis- treatment
O Avoid caffeine, lactose, NSAIDs
O 1st line: loperamide
O 2nd line: mesalamine (pentasa/asacol)
3g/day
O 3rd line: budesonide 9mg/day for 6 weeks
O >80% remission rate by 6 weeks but relapse
rate 40%
O Can retreat if symptoms recur
Case 5
O 30 year old female
O Diarrhoea up to 48 times per day (!)
O Nocturnal diarrhoea 8x overnight
O Loose, watery, no blood or mucus
O No weight loss
O Trialled FODMAP, gluten free, vegetarian diet
Case 5
O Previous history of functional dyspepsia
O
O
O
O
2003- gastroscopy and barium swallow
normal
Colonoscopy 2011 normal including
biopsies
Taking 10 loperamide per day
Codeine + colofac
Denies family history or stressors
Case 5
O Blood tests: normal apart from CRP 5
O Stool tests: no WCC/RCC/growth on culture
O Fecal calprotectin and elastase normal
O Where to from here?
Case 5
O Admitted for inpatient investigations
O 24 hour watch with bowel monitoring and
fecal weighing
O  x6 small amounts of formed brown
motion over 24 hours in hospital
O Each motion ~50mL at most
O Discharged with diagnosis of irritable bowel
syndrome and referred to health
psychologist
Difficult diarrhoea
O Persistent diarrhoea despite multiple
O
O
O
O
negative investigations
Consider factitious diarrhoea (prevalence
may be as high as 4%)
May need inpatient tests
48 hour stool collection
Trial of fasting