To determine if a patient has Crohn’s disease, the physician may, in addition to a physical and examination, request a colonoscopy and an upper endoscopy. In the case of a colonoscopy, a small camera mounted with a light is inserted into the anus to exam the colon. In the case of an upper endoscopy, the camera is inserted through the mouth, and through the esophagus, stomach and first parts of the small intestine. A biopsy of the infected area may also be taken to confirm or determine whether the tissue is diseased.
In cases where the disease occurs in places that cannot be visualized through endoscopy, the small intestine may be viewed by performing a CT scan or MRI of the intestine. To visualize the tissue, the patient drinks a contrasting solution that improves viewing of the tissue temporarily. Other techniques involve swallowing a pill-sized camera that takes pictures as it progresses through the intestines.