Ulcerative colitis initially misdiagnosed as irritable bowel syndrome: A case report.

Background: Irritable bowel syndrome (IBS) and early ulcerative colitis (UC) share overlapping gastrointestinal symptoms, which may lead to misdiagnosis and delay in appropriate treatment. Case presentation: The patient presenting with abdominal pain and altered bowel habits was initially diagnosed with IBS based on symptoms, physical examination, and past medical history, in the absence of alarm features. However, despite one week of symptomatic treatment, the patient's condition worsened. Diagnostic assessment: Further evaluation including complete blood profile, abdominal ultrasonography, colonoscopy, and colonic biopsy was subsequently performed, which confirmed a diagnosis of inflammatory bowel disease consistent with ulcerative colitis. Conclusion: This case highlights the diagnostic pitfalls in differentiating IBS from early UC based solely on clinical presentation. Clinicians should maintain a high index of suspicion and pursue appropriate laboratory and endoscopic investigations when symptoms persist or worsen, to avoid misdiagnosis, treatment delay, and disease progression.