Overview

Microscopic colitis is a common and often under-recognized cause of chronic watery diarrhea. Although the colon appears normal during colonoscopy, inflammation is present at a microscopic level and can only be detected on biopsy. While symptoms can be disruptive, microscopic colitis is a benign and highly treatable condition. With appropriate evaluation and targeted therapy, most patients achieve good symptom control and maintain quality of life.

What Is Microscopic Colitis?

Microscopic colitis is an inflammatory condition of the colon that causes chronic, watery diarrhea. Unlike other types of colitis, the colon typically appears normal during colonoscopy. The inflammation can only be seen when tissue samples (biopsies) are examined under a microscope – hence the name microscopic colitis.

Microscopic colitis is more common than many people realize. It affects an estimated 4-25 people per 100,000 each year, and among individuals undergoing colonoscopy for chronic diarrhea, 15-30% are ultimately diagnosed with microscopic colitis.

What Causes Microscopic Colitis?

The exact cause of microscopic colitis is not fully understood. It is believed to result from an abnormal immune response in the colon in individuals who may be genetically predisposed.

Several factors are associated with an increased risk of developing microscopic colitis, including:

Medications

Certain commonly used medications have been linked to microscopic colitis, including:

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and aspirin
• Proton pump inhibitors (PPIs) used for acid reflux
• Selective serotonin reuptake inhibitors (SSRIs)
• Statins used to treat high cholesterol

Other Risk Factors

• Cigarette smoking
• Prior gastrointestinal infections
• Autoimmune conditions, such as thyroid disease, rheumatoid arthritis, or celiac disease
• Increasing age

Symptoms of Microscopic Colitis

The most common symptom is chronic, watery diarrhea, which may persist for weeks to months. Additional symptoms may include:

• Frequent bowel movements, including nighttime diarrhea
• Sudden urgency to have a bowel movement
• Abdominal pain or cramping
• Fecal incontinence
• Unintentional weight loss
• Joint pain
• Fatigue

Symptoms can range from mild to severe and may significantly affect quality of life if left untreated.

How Is Microscopic Colitis Diagnosed?

Microscopic colitis can only be diagnosed by biopsy. Because the colon usually looks normal during colonoscopy, small tissue samples must be taken and examined under a microscope by a pathologist.

For this reason, microscopic colitis may be missed if biopsies are not obtained during evaluation for chronic diarrhea. Careful sampling throughout the colon is essential for accurate diagnosis.

How Is Microscopic Colitis Treated?

Treatment is focused on reducing diarrhea, controlling inflammation, and improving quality of life. Management is individualized based on symptom severity and response to therapy.

• Medication review: If you are taking medications associated with microscopic colitis, your physician may recommend stopping or substituting them when medically appropriate.
• Smoking cessation: Smoking is strongly associated with microscopic colitis, and quitting is recommended.
• Budesonide (steroid therapy): Budesonide is a locally acting steroid that reduces inflammation in the colon.
• Maintenance therapy: Some patients require long-term, low-dose budesonide to prevent symptom recurrence.
• Advanced therapies: In rare cases where symptoms do not respond to budesonide, other immunosuppressive medications or biologic therapies may be considered.

What Does a Diagnosis of Microscopic Colitis Mean?

Microscopic colitis is a benign condition that is not associated with an increased risk of colon cancer and rarely requires surgery. While symptoms can be disruptive, most patients respond well to treatment and are able to achieve long-term symptom control.

With proper diagnosis and individualized care, microscopic colitis is a highly manageable condition.

At BonheurMD we provide careful evaluation and personalized treatment so that microscopic colitis can be effectively managed allowing patients to regain comfort, confidence, and digestive well-being.