Chronic Diarrhoea

Question 1

Approach to chronic diarrhoea:
- List all the causes of chronic diarrhoea
(and where to rule out)

Answer 1

Pitfalls: large differentials, to strike balance on exploration and going into adequate depth on key differentials

1. Infective - usually watery, occasionally bloody (dysentry)
   - Acute exposure - travel history, sexual history
   - Look for parasites and viruses (CMV), immunocompromised (HIV)
   (Think bacterial, viral, PTB, parasitic, opportunistic)

Inflammatory
2. Inflammatory bowel disease - skin tags, ulcers, arthritis, uveitis, pyoderma, associated rheum condition/psoriasis
3. Ischaemic colitis - abdominal angina, atrial fibrillation
4. Radiation colitis - recent radiotherapy, malignancy
5. Invasive infections

Malabsorption - steatorrhoea, weight loss
6. Chronic pancreatitis
7. Cystic fibrosis
8. Coeliac disease - sensitive to gluten
9. Bacterial overgrowth - abnormal GI motility, scleroderma* (favourite)
10. Post-surgical - short gut, post-cholecystectomy

Drugs and medication - ask PMH and list of medications
11. Chemotherapy, methotrexate, anti-TNF
12. Antibiotics use
13. Osmotic effects (electrolyte salts)

Metabolic
14. Hyperthyrodism - symptoms and signs
15. Carcinoid syndrome - episodic diarrhoea, flushing, bronchospasm

Malignancy and infiltrative
16. Colon cancer
17. Amyloidosis
18. GI lupus

Question 2

History taking for chronic diarrhoea

Answer 2

1. Diarrhoea
   - Frequency/day, amount, consistency, colour, odour
   - Progression
   - PR bleeding or dysentery - blood in the stool? mixed with stool or separated on wiping?
   - Nocturnal diarrhoea (IBD)
   - Tenesmus (IBD, rectal cancer)
   - Steatorrhoea - oily, foul smelling, difficult to flush
2. Other GI symptoms
   - Abdominal pain - site, character, radiation, duration, pain score, alleviating and aggravating factors
   - Vomiting - frequency, content, colour, blood streak
   - Fever
3. Complications
   - Dehydration
   - Electrolyte imbalance
   - Appetite and weight
4. Family history - similar chronic diarrhoea, GI diseases, malignancy
5. Social history
   - Smoking, cigarette, sexual history
   - Travel history, food exposure, antibiotics use
   - Allergy history
6. Screening questions for identification of cause*

Question 3

Screening questions for chronic diarrhoea

Answer 3

1. Joint and back pain - extraintestinal manifestation of IBD
2. Skin rashes - dermatitis herpetiformis in coeliac disease
3. Red eyes - anterior uveitis
4. Dry eyes, dysphagia, GERD, vomiting - GI manifestation of scleroderma
5. Haematemesis - gastric vascular ectasia
6. Fecal incontinence
7. Raynaud’s phenomenon

Question 4

Action plan for chronic diarrhoea

Answer 4

1. Involvement of multidisciplinary team - gastroenterologist, dietitian +/- other specialties based on symptoms
2. Blood - FBC, RP, LFT, CRP, electrolytes
3. OGD and colonoscopy with biopsy
4. Stool ME, culture, C-diff toxin, parasites
5. Fecal calprotectin - inflammatory bowel disease
6. Coeliac screen - anti-endomysial, anti-tissue transglutaminase
   Ab, serum IgA
7. TFT
8. ASCA, p-ANCA - distinguish Crohn’s vs UC
9. Fecal fat estimation
10. Fecal elastase - exocrine pancreatic insufficiency
11. Hydrogen breath test - SIBO