Chronic Diarrhoea

DIARRHOEA
Chronic - 

Causes
1. Medications

2. Osmotic Diarrhoea 
Osmotic gap between stool measured and estimated > 50
a. Carbohydrate malabsorption - chronic post - prandial dirrhoea, distension, bloating, flatulence - diary ( lactose), fruits ( fructose), artificial sweeteners ( sorbitol)
processed foods n soft drinks, alcohol. Resolve during fasting.
Inv - Elimination trial for 2-3 weeks / H2 breath test
b. Laxatives - Antacids

3. Secretory Diarrhoea
watery with normal anion gap. eg bile salt malabs

4. Inflammatory - IBD - but occurs with pain, fever, weight loss, hematochezia

5. Malabs syndromes - weight loss, diarrhoea, steatorrhoea

6. Chronic infns - Giardia

7. Metabolic - Thyroid, DM


CF - 
diarrhoea - continuous / intermittent, relation to meals, at night / fasting ( secretory and not malabs)


INV - 
1. Routine - CBC, SE, LFT, Calcium, Phosphorous, ALb, TSH, Vit A and D, ESR, CRP
2. Stool - Ova, Cyst, FOBT, Stool Antigen Assays, Fecal fat ( malabs)
3. Endoscopic exam and mucosal biopsy 
4. CT 


TR- 
1. Loperamide - 4mg initially, then 2mg after each loose stool ( max 8 mg / day)
2. Diphenoxylate with atropine - 1 tid / qid
3. Codeine 
4. Clonidine - 0.1 - 0.3 mg bd in secretory diarrhoea ( inhibits secretion) 
5. Octreotide - 50 - 250 mcg s/c tid
6. Bile salt binders - Cholestyramine 2- 4 mg od/ tid in bile salt diarrhoea