Ulcerative colitis

Ulcerative colitis is an inflammatory disease of the bowel that usually affects the distal end of the large intestine and rectum. It has no known cause, although there is a genetic component to susceptibility. more...

Symptoms

• Chronic diarrhoea (sometimes bloody). Other symptoms may include abdominal pain and discomfort, bloating, and nausea.
• No infective cause of diarrhea found.
• Inflammatory changes are most often confined to the left side and distal parts of the large intestine, however, any part of the colon can be affected. Inflammatory changes can expand over time and affect larger areas of the colon. Long periods of inflammaton lead to fibrotic changes and can cause colon de-haustration, which results in the characteristic narrowing of the bowel.
• Disease variable in severity from patient to patient and time to time. This makes long-term prognosis very difficult, since a specific patient may remain in clinical remission for years between exacerbations.
• Significant risk of carcinoma after 10 years, which may in some cases require frequent surveillance biopsies or even prophylactic bowel removal.
• Patients may have other auto-immune features and extra-bowel complications including but not limited to iritis, uveitis, episcleritis, migratory polyarthritis, sacroiliitis, erythema nodosum, fingertip clubbing, ankylosing spondylitis and primary sclerosing cholangitis.
• Fistula formation is rare but does occur. However, unlike Crohn's disease, the probability of recurrence is low. Anal fissures are unfortunately much more common, and are in fact the very mechanism through which fistulas can be formed (although rarely) in ulcerative colitis patients - deep fissures can reach glands in the anal walls which then become infected and form abscesses which, in turn, lead directly to fistula formation.
• Often found in former smokers. Stopping smoking can cause a reduction in the protective mucus lining the colon. When this protective mucus is reduced, the bacteria in the colon can attack the colon lining causing the immune system to become active and fight the bacteria. For unknown reasons, this causes damage to the lining (ulcers) of the colon walls in one or more places. Resumption of nicotine either through patches or smoking can extend remission time although the benefits versus the other health risks of smoking are questionable.

Comparison to Crohn's disease

Ulcerative colitis is similar to Crohn's disease, but there are characteristic differences. Ulcerative colitis affects only the colon and cannot "migrate" to the small intestine, while Crohn's disease can affect the entire digestive tract. Complete colon removal can thus be considered a "cure" for ulcerative colitis. Ulcerative colitis is usually confined to the mucosal and submucosal lining of the colon, and affects whole areas of intestine. Crohn's disease, on the other hand tends to be patchy, and affect more layers of intestine, being transmural in nature. Due to the nature of the inflammation, ulcerative colitis rarely requires resection surgery in contrast to Crohn's disease where such surgery is often needed due to dangerous bowel obstructions and other complications. However, the risk of colorectal cancer development in ulcerative colitis patients is significantly greater (up to 5 times) than general population after 10 years following the diagnosis.

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