Most people are confused as to the difference between the two. The main differences between ulcerative colitis and Crohn's disease are described below.

Location of inflammation

In Crohn's disease, the location of the inflammation may occur anywhere along the digestive tract. In ulcerative colitis the large intestine (colon) is typically the only site that is affected. However, in some people with Ulcerative Colitis the last section of the small intestine, the ileum, may also show inflammation.

Symptoms

Many symptoms of Ulcerative Colitis and Crohn's Disease are similar, but there are some subtle differences. Ulcerative Colitis patients tend to have pain in the lower left part of the abdomen, while Crohn's Disease patients commonly (but not always) experience pain in the lower right abdomen. With Ulcerative Colitis, bleeding from the rectum during bowel movements is very common, and bleeding is mUlcerative Colitish less common in patients with Crohn's Disease.

Pattern of inflammation

The pattern that each form of IBD takes in the digestive tract is very distinct. Ulcerative Colitis tends to be continuous throughout the inflamed areas. In many cases, Ulcerative Colitis begins in the rectum or sigmoid colon, and spreads up through the colon as the disease progresses. In Crohn's Disease, the inflammation may occur in patches in 1 or more organs in the digestive system. For instance, a diseased section of colon may appear between two healthy sections.

Appearance

 In a colon that has Crohn's Disease, the wall may be thickened and, because of the intermittent pattern of diseased and healthy tissue, may have a irritated appearance. In Ulcerative Colitis, the colon wall is thinner and shows continuous inflammation with no patches of healthy tissue in the diseased section. Granulomas are inflamed cells that become lumped together to form a lesion. Granulomas are present in Crohn's Disease, but not in Ulcerative Colitis.

In Ulcerative Colitis, the lining of the large intestine is ulcerated. These ulcers do not extend beyond this inner lining. In Crohn's Disease, the ulceration is deeper and may extend into all the layers of the bowel wall.

Complications

In Crohn's Disease, strictures, fissures, and fistulas are not uncommon complications. These conditions are less frequently found in cases of Ulcerative Colitis.