IBS vs Microscopic Colitis: The Invisible Inflammation Only Biopsies Can Find
Microscopic colitis causes chronic watery diarrhea that looks exactly like IBS-D on every test except one: random colonic biopsies. The colon appears visually normal on colonoscopy, which is why the diagnosis is missed unless the endoscopist takes tissue samples. It is most common in women over 50 and responds well to budesonide, a treatment not used for IBS.
Current Consensus
- Microscopic colitis is diagnosed only by random colonic biopsies taken during colonoscopy; the mucosa appears grossly normal.
- It accounts for 10 to 15 percent of chronic watery diarrhea cases investigated by colonoscopy.
- The two subtypes are collagenous colitis and lymphocytic colitis, both responding to the same treatment.
- Budesonide is the first-line treatment with response rates exceeding 80 percent.
- Common medications associated with microscopic colitis include PPIs, NSAIDs, and SSRIs.
Open Questions
- Whether all IBS-D patients undergoing colonoscopy should have routine random biopsies to rule out microscopic colitis.
- The mechanism by which PPIs, NSAIDs, and SSRIs trigger microscopic colitis in susceptible individuals.
- Long-term relapse rates and optimal maintenance therapy after initial budesonide response.
- Whether microscopic colitis exists on a spectrum with IBD or is a fundamentally distinct condition.
- The role of autoimmunity in microscopic colitis pathogenesis.
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Each article includes cited sources, a medical review placeholder, and a clear distinction between what is established and what is still being studied.
Can Microscopic Colitis Be Misdiagnosed as IBS? The Invisible Inflammation
Microscopic colitis is frequently missed because the colon looks normal on colonoscopy. Learn why biopsies are often skipped, which drugs cause it, and how budesonide helps.
IBS vs Microscopic Colitis: How to Tell the Difference
Microscopic colitis causes chronic watery diarrhea but looks normal on colonoscopy. Learn the key differences from IBS, who is most at risk, and why biopsies matter.
Testing for Microscopic Colitis When IBS Treatment Is Not Working
If IBS-D treatments are failing, microscopic colitis may be the cause. Learn the biopsy protocol, medication review steps, and how a budesonide trial can confirm the diagnosis.
Medical Disclaimer: The content in this section is for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment. Always consult with a qualified healthcare professional before making changes to your health regimen. GLP1Gut is a tracking tool, not a medical device.