Upper gastrointestinal endoscopy is used to evaluate upper gastrointestinal symptoms in patients with inflammatory bowel disease. This article discusses the procedure, which may allow for the diagnosis of Crohn's disease of the esophagus, stomach, and/or duodenum. Biopsies of normal gastric mucosa in patients with indeterminate colitis may be helpful in making a diagnosis of Crohn's colitis. Upper gastrointestinal endoscopy may allow for therapeutic intervention in terms of bleeding and stricturing disease.