Ulcerative colitis

What it is

Inflammatory bowel disease is a group of related conditions characterized by idiopathic inflammation of the GI tract. The two most common are Crohn's disease and ulcerative colitis, both of which cause macroscopic inflammation. Ulcerative colitis is isolated to the large bowel; it always involves the rectum and may progress proximally. Although several features differentiate Crohn's disease from ulcerative colitis, the overlap between them is significant.

How it presents

The picture is of the rectum and the left colon, not of the small bowel:

• Rectal bleeding is very common, in 90%.
• Diarrhea is frequent, mucous and bloody, in small volume stools.
• Urgency and tenesmus are common.
• Abdominal pain is uncommon and comes before defecation.
• Fever is uncommon, and a palpable mass is rare.

Extraintestinal manifestations occur in both Crohn's disease and ulcerative colitis. The most common are oral aphthous ulcers, arthralgia and back pain, indicating ankylosing spondylitis or sacroiliitis. Eye redness, pain and swelling may result from uveitis or scleritis. Skin manifestations include pyoderma gangrenosum and erythema nodosum, and liver involvement most commonly means PSC.