Presented by Dr. Rabeea Zaki Chronic Diarrhea Presented by Dr. Rabeea Zaki

Essentials of Diagnosis Diarrhea > 4 weeks Classification: Medications Osmotic Diarrhea Secretory Diarrhea Inflamatory Diarrhea Malabsorption conditiions Motility disorders Chronic Infections Systemic disorders

General Considerations Medications: Cholinesterase inhibitors SSRI ARBs PPIs NSAIDs Metformin Allopurinol Orlistat

General Considerations Osmotic diarrhea: Resolves during fasting Secretory Diarrhea: Little change in stool output during fasting Increased intestinal secretion or decreased absorption

General Considerations Malabsorption disorders: Small mucosal intestinal diseases Intestinal resections Lymphatic obstruction Small intestinal bacterial overgrowth Pancreatic insufficiency Motility disorders: Surgery Systemic disorders

General considerations Chronic infections: Giardiasis, Amebiasis Immunocompromised patients susceptible to mycobacterium avium intracellulare, microsporidia, cyptosporidum, cytomegalovirus, cyclospora Chronic Systemic Conditions: Thyroid disease, diabetes, collagen vascular disease Alterations in motility or intestinal absorption

Clinical Findings Osmotic diarrheas: Secretory Diarrheas: Abdominal distension Bloating Flatulence Secretory Diarrheas: High volume (>1 L/day) watery diarrhea Dehydration Electrolyte imbalance

Clinical Findings Inflamatory Conditions: Malabsorption Syndromes Abdominal pain Fever Weight Loss Hematochezia Malabsorption Syndromes Osmotic Diarrhea Steatorrhea Nutritional Defeciencies

Features of Malabsorption

Differential Diagnosis Common Causes: IBS Parasites Caffeine Laxative abuse Osmotic causes: Lactase defeciency Medications: antacids, lactulose, sorbitol, olestra Factitious: magnesium containing antacids or laxatives

Differential Diagnosis Secretory Diarrhea Hormonal: ZE syndrome, Carcinoid, VIPoma,medullary thyroid carcinoma, adrenal insufficiency Laxative abuse: cascara, senna Medications Inflamatory Bowel conditions: IBD Microscopic colitis Cancer with obstruction and pseudodiarrhea Radiation colitis

Differential Diagnosis Malabsorption Small bowel: Celiac disease, whipple disease, tropical sprue, eosinophillic gstroenteritis, small bowel resectin Crohns disease Lymphatic obstruction: Lymphoma, carcinoid, tuberculosis Pancreatic insufficiency, Chronic pancreatitis, Cystic Fibrosis, Pancreatic Cancer Bacterial overgrowth eg diabetes, Reduced bile salts:ileal resection, chrons disease, post cholecystecomy

Differential Diagnosis Motility disorders IBS Postsurgical: vagotomy, partial gastrectomy, blind loop with bacterial overgrowth Chronic Infections: Parasites: Giardiasis, amebiasis, strongylodiasis Systemic disorders: Diabetes, Hyperthyroidsim, Scleroderma

Diagnosis Laboratory Tests: Blood CP, Serum electrolytes, LFTs, Ca, Phosphorous, Albumin, TSH INR, ESR, CRP Serologic testing: Tissue transglutaminase antibodies and antiendomysial antibodies recommended for most patients with signs of malabsorption

Diagnosis Stool Studies: Analyze stool sample for ova and parasites, electrolytes (osmotic gap), qualitative staining for fat, occult blood, leukocytes, lactoferrin Leukocytes or lactoferrin: suggest IBD Giardia and entemeba hystolytica may be detected in wet mounts Cryptosporidium and cyclospora are found with modified acid fast staining Increased osmotic gap suggests osmotic diarrhea or malabsorption Positive fecal fat stain suggests malabsorption disorder

Diagnosis 24 hour stool collection for weight and quantitative fecal fat Stool weight < 200 g/ 24 hrs excludes diarrhea and suggests some functional disorder like IBS Stool weight > 200 g/24 hrs confirms diarrhea Stool weight 1000-1500 g/ 24 hrs secretory diarrhea Fecal fat > 10 g/24 hrs suggest malabsorption disorder

Diagnosis Suspected malabsorption: Suspected Secretory Diarrhea: obtain serum folate, B12, S.iron, Vitamin D, Vitamin A and PT Suspected Secretory Diarrhea: Obtain serum VIP (vipoma), chromogranin A (carcinoid), calcitonin (medullary thyroid carcinoma), gastrin (ZE syndrome), glucagon, urine 5-hydroxyindoleacetic acid (carcinoid)

Diagnosis Imaging Studies: Abdominal CT: Pancreatitis, Pancreatic carcinoma, Neuroendocrine tumors Small intestinal imaging with barium, ct and MRI: crohns disease, small bowel lymphoma, carcinoid and jejunal diverticula Somatostatin receptor scintigraphy: Neuroendocrine tumours

Diangosis Diagnostic procedures: Sigmoidoscopy, Colonoscopy with mucosal biopsy: IBD and melanosis coli Upper endoscopy with small bowel biopsy: Celiac disease, whipple disease, AIDS related cryptosporidium, microsporidia and mycobacterium avium intracellulare infection Breath hydrogen test to diagnose bacterial overgrowth

Treatment Medications: Loperamide (imodium): 4mg orally initially then 2 mg after each loose stool (Max 16 mg/d) Diphenoxylate with atropine (Lomotil): 1 tablet three or four times daily as needed Codein 15-60mg orally or tincure of opium helpful in chronic intractable diarrheas Clonidine orally or clonidine patch is helpful in secreotry diarrheas, diabetic diarrhea and cryptosporidiasis

Treatment Medications: Therapeutic Procedures: Octreotide 50 mcg to 250mcg three times daily subcutaenously is helpful in case of secreotry diarrheas due to neuroendocrine tumours and AIDS related diarrheas Cholestyramine Resin: may be given orally in case of bile salt induced diarrhea secondary to intestinal resection or ileal disease Therapeutic Procedures: Consider discontinuing medications causing diarrhea

Outcome Complications: Dehydration Electrolyte Imbalance Malabsorption, Weight Loss and vitamin defeciencies

Questions Features of Malabsorption include all of the following except Steatorrhea Secretory Diarrhea Peipheral Neuropathy Acrodermatitis enteropathica

Answer 2. Secreotry Diarrhea

Question Which of the following statement is true? Stool weight 1000-1500 suggest inflamatory diarrhea Stool weight > 200 confirms secretry diarrhea Stool weight < 200 excludes diarrhea Fecal fat < 10 g/d suggests malabsorption disorder

Answer 3. Stool weight < 200 excludes diarrhea

Take Home Message Chronic diarrhea lasts more than 4 weeks. Has wide range of causes. Common Causes are IBS, parasites, Caffeine and Laxative abuse Careful assessment and detection of the underlying cause is needed to prevent serious sequele.

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