Microscopic Colitis

Abdominal pain, cramping, chronic watery diarrhea, urgency, and fatigue can take over daily life. If tests for infection are negative and the colon looks normal on camera, you may still have an inflammatory condition called microscopic colitis (MC). This page explains what MC is, how it is diagnosed, and how care teams—including CarePoint Infusion in Beachwood—support patients across Northeast Ohio when advanced therapies are prescribed.

What Is Microscopic Colitis?

Microscopic colitis is a type of inflammatory bowel disease that affects the colon. The name refers to the fact that inflammation is seen only on pathology review of biopsies—not always with the naked eye during colonoscopy. The lining may look pink and normal on video, while tissue samples show characteristic changes.

The two most discussed subtypes are:

• Collagenous colitis — a thickened band of collagen beneath the surface epithelium.
• Lymphocytic colitis — increased lymphocytes within the surface lining.

Symptoms and treatment often overlap between subtypes. MC is distinct from Crohn’s disease and ulcerative colitis, though it shares some treatment approaches. For a broader look at biologics in IBD, see our inflammatory bowel disease & biological therapy overview and gastroenterology infusion services at CarePoint.

Common Symptoms

Features often include:

• Chronic watery, non-bloody diarrhea (sometimes many times per day)
• Urgency and, for some people, incontinence
• Nocturnal diarrhea (symptoms that wake you from sleep)—a clue that evaluation beyond IBS alone may be needed
• Abdominal pain, cramping, bloating
• Unintentional weight loss, fatigue, or dehydration in severe cases

Because these symptoms overlap with irritable bowel syndrome (IBS), celiac disease, bile acid diarrhea, and other conditions, the right tests matter.

Who Is at Risk? Triggers to Review

MC is more often diagnosed in older adults and is more common in women than in men in many studies. Associations and possible triggers include:

• Smoking — strong risk factor; quitting is often emphasized in care plans.
• Medications — NSAIDs, proton pump inhibitors (PPIs), and some other drug classes have been linked in observational research; never stop a prescription without your prescriber’s plan.
• Autoimmune conditions — overlap with celiac disease, thyroid disease, and others occurs; your doctor may screen selectively.
• Alcohol — can worsen symptoms for some patients.

For a current clinical summary, many providers reference review literature in journals such as those indexed on PubMed.

How Microscopic Colitis Is Diagnosed

The gold standard is colonoscopy with multiple biopsies, even when the mucosa looks unremarkable. A pathologist examines the samples under a microscope to confirm collagen thickening, lymphocytic infiltration, or related findings.

Your team may also order blood tests, celiac serology, stool studies, or other tests to rule out mimics (infection, celiac disease, medication effects, etc.). Fecal calprotectin can be normal in MC, so a “normal” result does not always exclude the diagnosis—clinical context and biopsy remain central.

Treatment Overview

Management is individualized. Common themes include:

Iron Deficiency and Chronic Diarrhea

Ongoing diarrhea and inflammation can contribute to iron deficiency or anemia. If your provider recommends IV iron instead of oral iron, we offer iron infusion therapy in the same outpatient setting.

Lifestyle and Self-Care

Helpful strategies often include hydration with electrolytes, identifying food triggers during flares, smaller meals, and stress management. Diet is not one-size-fits-all; a registered dietitian with GI experience can help. Patient organizations such as the Crohn’s & Colitis Foundation and Guts UK publish supportive materials.

Frequently Asked Questions