Unmasking Parasitic Colitis Mimicking Inflammatory Bowel Disease

Parasitic infections may clinically mimic inflammatory bowel disease (IBD), particularly in patients with underlying liver cirrhosis, creating substantial diagnostic uncertainty. We describe a 27-year-old Egyptian male with presumed autoimmune hepatitis (AIH)-related cirrhosis who presented with abdominal pain and bloody diarrhea. Endoscopic evaluation suggested IBD; however, histopathology demonstrated eosinophilic colitis. Subsequent stool and serologic testing confirmed co-infection with Schistosoma mansoni and Strongyloides stercoralis. Treatment with antiparasitic therapy resulted in marked clinical improvement. This rare case of dual parasitic infection underscores the importance of detailed migration and residence history in endemic regions and freshwater exposure history, as these parasites can cause presinusoidal portal hypertension and progressive hepatic fibrosis. Parasitic etiologies should remain in the differential diagnosis for gastrointestinal symptoms in patients from endemic regions to avoid misdiagnosis and potentially harmful immunosuppressive therapy. Overall, these findings suggest that the parasitic infection likely contributed significantly to the patient’s hepatic fibrosis, potentially mimicking or exacerbating the presumed AIH-related cirrhosis rather than representing purely isolated autoimmune disease.