Ileocolonoscopy is regarded as the diagnostic procedure of choice for patients presenting with abdominal pain, chronic diarrhea, and suspicion of inflammatory bowel diseases. The widespread use of endoscopy has led to an increase of biopsies of the colon and terminal ileum. The diagnostic yield of biopsies of the terminal ileum is not established and is low in unselected patients. Retrospective studies have assessed the diagnostic value of these biopsies in comparison to the indication for ileoscopy and the endoscopic findings. The data suggest that biopsies of the terminal ileum are mainly helpful in patients with inflammatory diarrhea and/or suspected inflammatory bowel disease.