Data is conflicting, and while some evidence suggested that IBS patients are at increased risk for organic disease over the long-term compared with individuals in the general population, absolute rates remain low. With respect to CRC, the risk is low in the general population <50 years of age, and IBS is not a recognized risk factor for CRC. There appears to be little or no evidence that IBS increases the risk of CRC over the short-term compared with the general population, with the exception of a study from Taiwan that suggested a 3.6 times higher 10-year risk in the IBS group compared with the non-IBS group Finally, data do not support the idea that patients may be reassured by a normal colonoscopy. Therefore, the consensus group concluded that routine colonoscopy is generally not warranted in IBS patients <50 years of age, and alarm symptoms do not appear to increase the risk of CRC sufficiently to warrant routine colonoscopy. Alarm features that warrant investigation include, but are not limited to, rectal bleeding, weight loss and anemia.
GRADE: Strong recommendation, very low-quality evidence
Sources:
Moayyedi P et al. Canadian Association of Gastroenterology Clinical Practice Guideline for the Management of Irritable Bowel Syndrome (IBS). J Can Assoc Gastroenterol. 2019 Apr;2(1):6-29. PMID: 31294724. https://pubmed.ncbi.nlm.nih.gov/31294724/