LAS VEGAS—The lack of a single gold standard test for inflammatory bowel disease contributes to misdiagnosis of other gastrointestinal conditions with overlapping symptoms, subjecting patients to unnecessary therapies and potential harm. A new study exploring so-called “IBD mimics” has shed some light on this tricky diagnostic territory.
The research examined a sample of perplexing case studies in which IBD was initially suspected but ultimately ruled out. Findings from the study presented at the 2024 Crohn’s & Colitis Congress showed that nearly one in five patients referred to specialists for presumed IBD turned out to have other conditions that mimicked IBD symptoms (abstract P001). In addition, according to investigator Hannah W. Fiske, MD, nearly 40% of these misdiagnosed patients received prescription biologic medications before the true diagnosis was discovered.
Although the high rate of misdiagnosis uncovered in this difficult cohort should not be overgeneralized, said Dr. Fiske, a resident at Brown University/Rhode Island Hospital, in Providence, it spotlights how even specialists struggle to distinguish IBD from imposters.
“Ultimately, these can be very tricky patients to diagnose,” Dr. Fiske told Gastroenterology & Endoscopy News. “I think this study shows that if nothing’s working and there’s a doubt in your mind, there are many other diseases that it could be that mimic IBD.”
These findings emerged from an analysis of hundreds of hours of video case presentations from IBD Live, a weekly virtual group consultation series in which GI specialists discuss their most perplexing cases. Dr. Fiske and her co-investigators manually reviewed 371 complex cases with the aim of identifying cases in which IBD was initially suspected but ultimately proved to be mimics.
Of 371 cases, the investigators found 65 (17.5%) that turned out not to be Crohn’s disease or ulcerative colitis as originally suspected. The mimics ranged from varying types of cancer to colitis to systemic diseases. Other mimics were drug-induced.
Despite the misdiagnosis, 25 of 65 patients (38.5%) were treated with biologic therapies, including one patient who cycled through five different biologics before getting the right diagnosis. Five patients suffered adverse events from the unnecessary medications that were serious enough to warrant discontinuation.
Although six cases had alternative conditions treatable with biologics, the analysis raises questions about the frequency of IBD misdiagnosis among complex referrals and the use of powerful biologic medications without adequate confirmation. According to Dr. Fiske, additional testing such as endoscopic biopsies, pathology review, and a thorough history and physical exam were pivotal in reaching the correct diagnoses.
“These findings highlight the challenge of definitively confirming or excluding IBD and the need for more meticulous testing,” Dr. Fiske noted. “Exhausting other explanations before prescribing risky fifth-line biologics could prevent much unnecessary patient suffering.”
Ashwin Ananthakrishnan, MBBS, MPH, a physician investigator in gastroenterology at Mass General Research Institute, in Boston, who was not involved in the research, underscored the significance of an accurate diagnosis in this setting. “I think this is an important study,” Dr. Ananthakrishnan told Gastroenterology & Endoscopy News. “It does not tell us how common the mimics are—mimics are likely uncommon and differ based on region, other risk factors, etc.—[but] it does tell us that, particularly in somebody whose disease is behaving differently from expected, it is important to take a step back and reconsider the IBD diagnosis.”
Calling that “a very important message for the audience,” he added: “Sometimes patients carry the label of a particular diagnosis, and we don’t think to question that diagnosis until several years later.”
—Chase Doyle
Dr. Fiske reported no relevant financial disclosures.
This article is from the May 2024 print issue.