The diagnosis of Crohn's disease is usually a combination of a patient's symptoms, exam findings, laboratory results and very often x-rays and a procedure called a colonoscopy which involves the use of a long flexible tube that has a digital camera on the end and through which biopsies of the tissue can be obtained. The most common location for Crohn's disease is in the last portion of the small intestine and the first portion of the colon, but the disease may involve any portion of your gastrointestinal tract, from your mouth to your anus.

A diagnosis of Crohn's disease is made after all of these things are taken into consideration by an experienced health care provider. Before Crohn's disease can be confirmed, infections must be excluded since they can look like Crohn's disease in some patients.