During a sigmoidoscopy, which finding is typical in a patient with Crohn's disease?

In patients with Crohn's disease, findings during a sigmoidoscopy often include intermittent longitudinal mucosal ulcers and fissures. This characteristic appearance is due to the transmural inflammation associated with Crohn's disease, which can lead to deep ulcers that penetrate through the layers of the bowel wall. The presence of fissures is typical in this condition, as the inflammation can cause not just ulcerations but also fissures that can be painful and significant in nature.

Also relevant is how these features compare to findings typical of other conditions affecting the bowel. For example, while diffuse ulceration and bleeding might suggest a more acute inflammatory or infectious process, it is not as characteristic of Crohn's disease, which typically showcases a more segmental and patchy distribution of lesions. Similarly, the presence of rectal pseudopolyps and sheets of white blood cells indicate different pathological changes which may be more common in ulcerative colitis rather than the segmental inflammation that is hallmark of Crohn's disease. Intermittent longitudinal mucosal ulcers and fissures best exemplify the unique pathology of Crohn's disease during endoscopic evaluation.