Irritable Bowel Syndrome (IBS) and Colonoscopy

Get a high resolution pdf of the colon cancer poster here.

Should I have a colonoscopy to diagnose IBS?

A complete history, physical examination, and tailored laboratory and imaging studies is enough to diagnose IBS in most patients. Diagnostic studies such as hemoglobin and C-reactive protein levels may also be helpful. Patients with IBS-D or IBS-M should have serologic testing for celiac disease. Routine serologic or genetic testing is not indicated in patients with IBS. 

The 2009 American College of Gastroenterologists (ACG) evidence-based position statement on the management of IBS does not recommend laboratory testing or diagnostic imaging in patients younger than 50 years with typical IBS symptoms and without “warning signs”.  Patients with warning signs, such as bleeding, anemia, chronic diarrhea, older age, history of colon polyps, family history of certain GI illnesses (eg, inflammatory bowel disease, celiac sprue, colorectal cancer) should have a colonoscopy. 

Patients aged 50 years and older should have more extensive testing, including a colonoscopy. A screening colonoscopy should be performed according to published guidelines (see poster above).

Patients with persistent dyspepsia, weight loss, symptoms which suggest malabsorption, or possible celiac disease should have an esophagogastroduodenoscopy with possible biopsy.

A reminder on screening colonoscopy:

✅ No family history->screen at 45 (African American/risk factors) or 50.

✅ Family history->screen at 40 or earlier.

✅ If symptoms (blood in stool, rectal pain, change in stools, weight loss) at ANY AGE-> colonoscopy now.  

✅ Don’t let #COVID19 allow you to delay.

✅ If you cannot get a colonoscopy done for any reason, talk to your doctor about screening with an FIT Kit.


American College of Gastroenterology Task Force on Irritable Bowel Syndrome, Brandt LJ, Chey WD, et al. An evidence-based position statement on the management of irritable bowel syndrome. Am J Gastroenterol. 2009;104 Suppl 1:S1-S35. doi:10.1038/ajg.2008.122

Medically reviewed by Onikepe Adegbola, MD PhD, founder, Casa de Sante

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