Microscopic Colitis is a form of Inflammatory Bowel Disease (IBD). Researchers are still learning more about microscopic colitis, but current research suggests that it may be an autoimmune response that leads to inflammation of the large intestine. Like most other autoimmune conditions, there is no single cause. Instead, multiple factors may contribute, including genetics, environment, some medications, other autoimmune conditions, previous infections, stress, and smoking. Microscopic colitis is more common in women, particularly those over age 60 or post-menopausal. The hallmark symptom is frequent, water diarrhea, but people may experience a range of digestive symptoms.
Symptoms of Microscopic Colitis
Common symptoms of microscopic colitis include:
- Watery diarrhea (5-10 times per day)
- Stool urgency or incontinence
- Abdominal pain or cramping
- Loud or noisy digestion
- Unintentional weight loss
- Dehydration
There are two main types of microscopic colitis, which differ slightly in their appearance and underlying physiology but cause similar symptoms and respond to similar treatments:
Collagenous colitis
Characterized by thick bands of collagen in the lining of the colon.
Lymphocytic colitis
Marked by an increased number of lymphocytes (a type of white blood cell) in the colon lining.
How is Microscopic Colitis Diagnosed?
Diagnosis typically begins with a review of symptoms and may include stool tests (to rule out infection or inflammation) and blood tests (to evaluate for autoimmune conditions). To confirm the diagnosis of microscopic colitis, a gastroenterologist should perform a colonoscopy and take a sample of the colon tissue, called a biopsy. The colon often appears normal during the procedure, but inflammation becomes evident under a microscope—hence the name microscopic colitis.
How is Microscopic Colitis Treated?
Treatment focuses on reducing inflammation, controlling symptoms, and preventing flare-ups. Depending on your symptoms, your healthcare provider may recommend one or more of the following approaches:
Corticosteroids (such as budesonide)
Budesonide is often the first-line therapy and helps most people achieve remission. It is preferred over other corticosteroids because it primarily acts in the gut, minimizing systemic side effects.
Low-fiber diet during flare ups
During a flare, the goal is to calm inflammation and reduce bowel irritation. Choose low-fiber, easy-to-digest foods such as refined grains, thoroughly cooked vegetables, and tender proteins like fish or ground meats. Avoid whole grains, nuts, seeds, and raw fruits or vegetables. A short-term liquid diet may also help during severe flares.
Anti-inflammatory diet between flares
When symptoms are under control, a Mediterranean-style diet rich in fruits, vegetables, whole grains, fish, nuts, and seeds may help reduce inflammation and support gut health.
Identifying and avoiding food triggers
High alcohol consumption has been identified as a possible risk factor for microscopic colitis. Therefore, limiting alcohol intake may help manage symptoms. While no specific foods are known to trigger microscopic colitis, avoiding foods that you are personally sensitive or allergic to can help reduce inflammation.
Anti-diarrheal medications
Anti-diarrheal medications like loperamide (Imodium) or diphenoxylate may help manage persistent diarrhea if other treatments are not effective.
Fiber supplements
Soluble fiber supplements, such as Metamucil, can help bulk up stools and improve stool consistency.
Living with a gastrointestinal condition can feel overwhelming, but the outlook for microscopic colitis is often positive. About 70–80% of people achieve remission—either with treatment or spontaneously—though relapses can occur in up to 25–30% of cases.
If you’re interested in learning how nutrition can help manage microscopic colitis, schedule an appointment with a registered dietitian. You can schedule online here or call 919-237-1337 (option 4).
