II. Epidemiology
- More common in older patients (age 50 years old and older)
- Causes 10% of Chronic Diarrhea cases
- Causes 10-15% of all Secretory Diarrhea
- Gender
- Women account for most cases
- Age 60 years is typical (<45 years in 25% of cases)
III. Risk Factors: Medications
- NSAID use for longer than 6 months
- Aspirin
- Statins
- Proton Pump Inhibitors
- Selective Serotonin Reuptake Inhibitors (SSRI)
IV. Associated Conditions
-
Irritable Bowel Syndrome
- Microscopic Colitis is present in 5-10% of Irritable Bowel Syndrome
- Celiac Disease
V. Symptoms
-
Chronic Watery Diarrhea
- Secretory Diarrhea (Diarrhea day and night regardless of Fasting)
- Abdominal Pain
- Weight loss
- Arthralgias
- Fatigue
VI. Labs
- Stool studies without microscopic blood or mucus
VII. Associated Conditions
- Celiac Sprue (5% of cases)
VIII. Diagnosis: Colonoscopy findings
- Normal gross appearance
- Biopsy of transverse colon (random biopsies) confirms diagnosis with one of two histologic patterns
- Lymphocytic Colitis
- Lamina propria with lymphocytic infiltrate
- Collagenous Colitis
- Subepithelial Collagen layer increased >10mm
- Lymphocytic Colitis
IX. Management
- Discontinue predisposing medications (esp. NSAIDs)
- Stop NSAIDs
- Stop Proton Pump Inhibitors (e.g. Omeprazole)
- Stop Statins
- Stop Selective Serotonin Reuptake Inhibitor
- Mild Symptoms
- Treat as Diarrhea predominant Irritable Bowel Syndrome
- Cholestyramine 4 grams qhs to 6 times daily
- Loperamide (Imodium) 2-4 mg four times daily prn (primarily before meals)
- Diphenoxylate
- Bismuth Subsalicylate
- Moderate Symptoms
- Budesonide AND
- Mild symptom management options
- Severe Symptoms
- Immunomodulators (6-Mercaptopurine, Methotrexate, Azathioprine, Infliximab)