Diagnosis of Irritable Bowel Syndrome: Primary Care Physicians Compared with Gastroenterologists

Objective: To examine disparities between primary care provider (PCP) and gastroenterologist diagnosis and management of irritable bowel syndrome (IBS). Setting: A 547-bed quaternary-care hospital within the Loyola University Healthcare System. Participants: 1000 patients aged 18-65 with an ICD-10 diagnosis of IBS Methods: We randomly selected 1000 patients aged 18 to 65 years within the Loyola University Healthcare System's electronic medical record with an ICD-10 diagnosis of IBS. Physician notes and diagnostic results were reviewed for documentation of symptoms fulfilling Rome IV criteria and resolution of symptoms. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of primary diagnoses assigned by PCPs and gastroenterologists were assessed along with number of diagnostic tests ordered. Results: The mean age (SD) was 45 (12) years, and 76.9% were female. Sensitivity of an IBS diagnosis by a PCP was 77.6% (95% CI 73.3-81.9), compared with 60.1% (95% CI 54.7-65.6) for a gastroenterologist. Specificity of an IBS diagnosis by a PCP was 27.5% (95% CI 23.5-31.5), compared with 71.1% (95% CI 64.6-77.5) for a gastroenterologist diagnosis of IBS. A gastroenterologist diagnosis of IBS carried a high PPV (77.3%, 95% CI 72.0-82.6) compared with 44.6% (95% CI 40.7-48.5) for a PCP. Of 180 patients with outcome data, 69.4% had resolution of symptoms at follow-up. Conclusion: The sensitivity of gastroenterologist diagnosis of IBS closely matches the sensitivity of Rome IV criteria in validation studies. The high specificity and PPV of gastroenterologists suggest more cautious diagnosis by gastroenterologists, with PCPs more likely to assign a diagnosis of IBS incorrectly or without sufficient documentation of symptoms fulfilling Rome IV criteria. Reported resolution rates suggest primary care management of IBS is appropriate, but PCPs may benefit from gastroenterologist consultation and diagnostic guidelines for greater specificity in diagnosing IBS.