Brief Overview: According to NIDDK, “Microscopic colitis is a chronic disease in which abnormal reactions of the immune system cause inflammation on the inner lining of your colon.” The most prominent symptom is chronic, watery, non-bloody diarrhea. It has two subtypes – lymphocytic and collagenous. Both subtypes have the same symptoms and the same treatment plan.
Prevalence: According to UpToDate, “The estimated incidence of collagenous colitis and lymphocytic colitis are 2.0 to 10.8 and 2.3 to 16 per 100,000 per year, respectively.”
Etiology: Microscopic colitis is caused by inflammation of the colon, but the cause of that inflammation is not always known.
Risk Factors:
- Female
- Age (average age of dx is 65yo)
- Certain medications: NSAIDs, PPIs, statins, SSRIs, H2 blockers, HRT and oral contraceptives, beta blockers
- Smoking
Commonly Associated Conditions:
- Autoimmune thyroiditis
- Type 1 diabetes
- Celiac disease
- Non-erosive, oligoarticular arthritis
- Psoriasis
- RA
Common Medications:
- Anti-diarrheal - Loperamide
- Oral budesonide (prednisone if budesonide not feasible)
- Other medications may be indicated if symptoms persist or do not response to prior treatment
Common Labs, Imaging, and Tests:
- Blood tests: CBC, ESR, CRP, ANA, RF, AMA, anti-TPA, celiac serology, CMP
- Stool test
- Endoscopy and colonic mucosa biopsy
- Colonoscopy
Common Symptoms:
- Chronic, non-bloody, watery diarrhea
- Abdominal pain
- Fecal urgency or incontinence
- Weight loss
- Fatigue
- Arthralgia, arthritis, and uveitis can occur
Common Treatments:
- Medications (see above)
- Smoking cessation
- If possible, discontinue any medications that are associated with microscopic colitis
Physical Findings:
- Typically, normal physical exam
- Abdominal tenderness
Potential Complications and Contraindications:
- Increased risk of acute pancreatitis
- Avoid NSAIDs
- Smoking cessation
General Health and Lifestyle Guidance:
- Alcohol avoidance
- Smoking cessation
- Limit/avoid artificial sweeteners and caffeine
- Maintain adequate hydration. Discuss your specific hydration/fluid intake recommendations with your healthcare provider
Suggested Questions to Ask Patients:
- How long have you had diarrhea, and how many times a day?
- Do you use NSAIDs, acid reducers, or antidepressants regularly?
- Have you noticed any food triggers for your symptoms?
- Do you have a history of autoimmune or gastrointestinal conditions?
- Are you experiencing weight loss or signs of dehydration?
Suggested Talking Points:
- Keep a symptom log/food diary to report to your healthcare provider
- Report any new, worsening, or persistent symptoms to your healthcare provider
Sources:
- UpToDate
- https://www.niddk.nih.gov/health-information/digestive-diseases/microscopic-colitis