Microscopic colitis (MC) is a common cause of chronic, non-bloody watery diarrhea characterized by inflammation in the lining of the colon. Unlike other inflammatory bowel diseases, the colon appears normal during a standard endoscopy, requiring a tissue sample to be examined under a microscope for diagnosis. This condition is categorized into two main subtypes: collagenous colitis, which features a thickened layer of collagen beneath the colon lining, and lymphocytic colitis, which shows an increased number of white blood cells called lymphocytes. Although the subtypes have distinct microscopic features, the symptoms and treatment approaches are generally the same. Effective management aims to reduce inflammation, control symptoms like diarrhea and abdominal pain, and improve the patient’s quality of life.
Initial Dietary and Lifestyle Modifications
A critical intervention is the immediate cessation of nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, as these are strongly associated with triggering or worsening MC symptoms. Smoking is also a known risk factor, and quitting tobacco is a necessary and highly recommended lifestyle change for patients.
Many patients find that certain dietary components can aggravate their symptoms, making personalized elimination a valuable strategy. Common culprits include caffeine, alcohol, and dairy products, which can all increase intestinal motility or contribute to irritation. Some individuals may benefit from temporarily limiting gluten, especially since a significant number of MC patients also have celiac disease.
Patients often find relief by temporarily adopting a low-fat or low-fiber diet during active flare-ups to ease the burden on the inflamed colon. Highly processed foods, artificial sweeteners, and high-fat meals are also frequently identified as symptom aggravators and should be reduced or avoided. Systematically identifying personal triggers with a healthcare provider or dietitian is an important non-pharmacological step.
Standard Pharmacological Interventions
For patients whose symptoms do not resolve after initial dietary and lifestyle changes, the standard medical approach focuses on reducing microscopic inflammation. The most effective first-line prescription medication is budesonide, a type of corticosteroid specifically formulated for targeted action in the gut. Budesonide is preferred because it has a high rate of first-pass metabolism in the liver, meaning most of the drug is deactivated before it can circulate throughout the body.
This unique mechanism minimizes the systemic side effects typically associated with traditional oral steroids, such as prednisone. The standard course involves a dosage of 9 milligrams daily for six to eight weeks to induce clinical remission. Although budesonide is highly successful at inducing remission, the disease often relapses after the medication is stopped.
In addition to anti-inflammatory treatment, anti-diarrheal agents are frequently used for symptomatic relief, particularly in milder cases or as an adjunct to budesonide therapy. Medications like loperamide work to slow the movement of the gut, decreasing the frequency of bowel movements. Although these agents can offer immediate relief from debilitating diarrhea, they address the symptom rather than the underlying inflammation.
Addressing Refractory Symptoms
Refractory microscopic colitis occurs when symptoms fail to improve or quickly return despite completing a full course of first-line budesonide therapy. For these chronic or severe cases, second-line medical therapies are considered to achieve sustained remission. This next step often involves the use of immunomodulators, such as azathioprine or mercaptopurine, which work by suppressing the overall immune response that drives the inflammation.
Response rates to these immunosuppressive drugs can be variable, and they require careful monitoring due to potential side effects. In patients with severe, non-responsive disease, biologic agents may be introduced. Examples include anti-tumor necrosis factor (TNF) therapies like infliximab or adalimumab, or integrin inhibitors like vedolizumab, which are more commonly used for other forms of inflammatory bowel disease.
Surgical intervention is extremely rare and is reserved as a last resort for patients with debilitating, unremitting symptoms that have failed all advanced medical treatments. This procedure typically involves a total or subtotal colectomy, the removal of the colon, which can offer a definitive resolution to the severe chronic diarrhea. The decision to pursue surgery is only made after exhaustive trials of medical therapy and careful consideration of the patient’s overall health and quality of life.
Long-Term Monitoring and Relapse Prevention
Maintaining symptom control and preventing the recurrence of active disease is the focus after achieving remission. Regular follow-up appointments with a gastroenterologist are necessary to monitor long-term status and screen for early signs of a relapse. Because budesonide is associated with a high rate of relapse upon withdrawal, a slow and cautious tapering schedule is often employed to give the gut time to adjust.
For individuals who experience frequent symptom recurrence, a low-dose maintenance regimen of budesonide, typically 3 to 6 milligrams daily, may be prescribed for several months or longer. This strategy is effective at prolonging remission for many patients while minimizing the risk of cumulative steroid side effects. Ongoing adherence to the previously identified dietary modifications remains important for long-term health, even when the disease is inactive.
Patients should be aware of the signs of an impending relapse, which commonly include an increase in the frequency of watery stools, greater urgency, or the return of abdominal cramping. Early recognition allows for prompt medical intervention, such as a temporary increase in anti-diarrheal medication or a short re-induction course of budesonide, which can prevent a full-blown flare-up. A vigilant, proactive approach to maintenance is the best path for sustained wellness.