Long-term condition: Ulcerative colitis

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Ulcerative colitis (UC) is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary symptoms of active disease are abdominal pain and diarrhea mixed with bloodWeight lossfever, and anemia may also occur.[1] Often, symptoms come on slowly and can range from mild to severe. Symptoms typically occur intermittently with periods of no symptoms between flares. Complications may include megacolon, inflammation of the eye, joints, or liver, and colon cancer.

The cause of UC is unknown.Theories involve immune system dysfunctiongenetics, changes in the normal gut bacteria, and environmental factors.Rates tend to be higher in the developed world with some proposing this to be the result of less exposure to intestinal infections, or to a Western diet and lifestyle. The removal of the appendix at an early age may be protective.Diagnosis is typically by colonoscopy with tissue biopsies. It is a kind of inflammatory bowel disease (IBD) along with Crohn's disease and microscopic colitis.

Signs and symptoms

Gastrointestinal

The clinical presentation of ulcerative colitis depends on the extent of the disease process. People with ulcerative colitis usually present with diarrhea mixed with blood and mucus, of gradual onset that persists for an extended period (weeks). They may also have weight loss and blood on rectal examination. The inflammation caused by the disease along with the chronic bleeding from the GI tract leads to increased rates of anemia. The disease may be accompanied by different degrees of abdominal pain, from mild discomfort to painful bowel movements or painful abdominal cramping with bowel movements.

Extent of involvement

Ulcerative colitis is normally continuous from the rectum up the colon. The disease is classified by the extent of involvement, depending on how far the disease extends:[medical citation needed]

  • Distal colitis, potentially treatable with enemas:
    • Proctitis: Involvement limited to the rectum
    • Proctosigmoiditis: Involvement of the rectosigmoid colon, the portion of the colon adjacent to the rectum
    • Left-sided colitis: Involvement of the descending colon, which runs along the person's left side, up to the splenic flexure and the beginning of the transverse colon
  • Extensive colitis: Inflammation extending beyond the reach of enemas:
    • Pancolitis: Involvement of the entire colon, extending from the rectum to the cecum, beyond which the small intestine begins

Pathophysiology

An increased amount of colonic sulfate-reducing bacteria has been observed in some people with ulcerative colitis, resulting in higher concentrations of the toxic gas hydrogen sulfide. Human colonic mucosa is maintained by the colonic epithelial barrier and immune cells in the lamina propria (see intestinal mucosal barrier). N-butyrate, a short-chain fatty acid, gets oxidized through the beta oxidation pathway into carbon dioxide and ketone bodies. It has been shown that N-butyrate helps supply nutrients to this epithelial barrier. Studies have proposed that hydrogen sulfide plays a role in impairing this beta-oxidation pathway by interrupting the short chain acetyl-CoA dehydrogenase, an enzyme within the pathway. Furthermore, it has been suggested that the protective benefit of smoking in ulcerative colitis is due to the hydrogen cyanide from cigarette smoke reacting with hydrogen sulfide to produce the non-toxic isothiocyanate, thereby inhibiting sulfides from interrupting the pathway.An unrelated study suggested that the sulfur contained in red meats and alcohol may lead to an increased risk of relapse for people in remission.[

Management

Medication

Ulcerative colitis can be treated with a number of medications, including 5-ASA drugs such as sulfasalazine and mesalazine. Corticosteroids such as prednisone can also be used due to their immunosuppressive and short-term healing properties, but because their risks outweigh their benefits, they are not used long-term in treatment. Immunosuppressive medications such as azathioprine and biological agents such as infliximab and adalimumab are given only if people cannot achieve remission with 5-ASA and corticosteroids. Infliximab or vedolizumab are recommended in those with moderate or severe disease.Such treatments are used less commonly due to their possible risk factors, including but not limited to increased risk of cancers in teenagers and adults, tuberculosis, and new or worsening heart failure (these side effects are rare).

 


Crohn's disease

Ulcerative colitis

Management

Mesalazine

Less useful

More useful

Antibiotics

Effective in long-term

Generally not useful

Surgery

Often returns following
removal of affected part

Usually cured by removal
of colon

 

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