ROSH Gastrointestinal Practice Exam

Which characteristic is associated with Crohn disease?

1. Continuous uninterrupted inflammation of the colonic mucosa

2. Rectal involvement occurs in all cases

3. Smoking appears to confer a protective effect

4. Transmural involvement with cobblestone appearance

The correct answer is: Transmural involvement with cobblestone appearance

The characteristic associated with Crohn disease is transmural involvement with a cobblestone appearance. Crohn disease is known for its ability to affect any part of the gastrointestinal tract, from the mouth to the anus, and it typically involves all layers of the bowel wall, leading to transmural inflammation. This depth of inflammation can cause a variety of structural changes in the intestine, including the characteristic "cobblestone" appearance seen during endoscopy or imaging studies, where the mucosal surface shows irregularities and ulcerations. This feature is significant because it helps differentiate Crohn disease from other forms of inflammatory bowel disease, particularly ulcerative colitis, which primarily involves only the mucosal layer of the colon and typically presents with continuous inflammation. The cobblestone appearance is indicative of the focal nature of the disease, where segments of normal intestine may be interspersed with inflamed areas. In addition to the transmural involvement, Crohn disease can also lead to complications such as fistulas and strictures due to the extensive inflammation affecting the entire bowel wall. Understanding these characteristics is crucial for effective diagnosis and management of the disease.