Ulcerative Colitis
Ulcerative colitis is a chronic inflammation of the large intestine (colon). The colon is the part of the digestive system where waste material is stored. The rectum is the end of the colon adjacent to the anus. In patients with ulcerative colitis, ulcers and inflammation of the inner lining of the colon lead to symptoms of abdominal pain, diarrhea, and rectal bleeding.
Causes of Ulcerative Colitis
Ulcerative colitis and Crohn's disease are caused by abnormal activation of the immune system in the intestines. The immune system is composed of immune cells and the proteins that these cells produce. These cells and proteins serve to defend the body against harmful bacteria, viruses, fungi, and other foreign invaders. Activation of the immune system causes inflammation within the tissues where the activation occurs. (Inflammation is, in fact, an important mechanism of defense used by the immune system.)Normally, the immune system is activated only when the body is exposed to harmful invaders. In patients with Crohn's disease and ulcerative colitis, however, the immune system is abnormally and chronically activated in the absence of any known invader. The continued abnormal activation of the immune systems causes chronic inflammation and ulceration. The susceptibility to abnormal activation of the immune system is genetically inherited
Symptoms of Ulcerative Colitis
Common symptoms of ulcerative colitis include rectal bleeding and diarrhea, but there is a wide range of symptoms among patients with this disease. Variability of symptoms reflects differences in the extent of disease (the amount of the colon and rectum that are inflamed) and the intensity of inflammation.Generally, patients with inflammation confined to the rectum and a short segment of the colon adjacent to the rectum have milder symptoms and a better prognosis than patients with more widespread inflammation of the colon. The different types of ulcerative colitis are classified according to the location and the extent of inflammation:
- Ulcerative proctitis refers to inflammation that is limited to the rectum. In many patients with ulcerative proctitis, mild intermittent rectal bleeding may be the only symptom. Other patients with more severe rectal inflammation may, in addition, experience rectal pain, urgency (sudden feeling of having to defecate and a need to rush to the bathroom for fear of soiling), and tenesmus (ineffective, painful urge to move one's bowels).
- Proctosigmoiditis involves inflammation of the rectum and the sigmoid colon (a short segment of the colon contiguous to the rectum). Symptoms of proctosigmoiditis, like that of proctitis, include rectal bleeding, urgency, and tenesmus. Some patients with proctosigmoiditis also develop bloody diarrhea and cramps.
- Left-sided colitis involves inflammation that starts at the rectum and extends up the left colon (sigmoid colon and the descending colon). Symptoms of left-sided colitis include bloody diarrhea, abdominal cramps, weight loss, and left-sided abdominal pain.
- Pancolitis or universal colitis refers to inflammation affecting the entire colon (right colon, left colon, transverse colon and the rectum). Symptoms of pancolitis include bloody diarrhea, abdominal pain and cramps, weight loss, fatigue, fever, and night sweats. Some patients with pancolitis have low-grade inflammation and mild symptoms that respond readily to medications. Generally, however, patients with pancolitis suffer more severe disease and are more difficult to treat than those with more limited forms of ulcerative colitis.
- Fulminant colitis is a rare but severe form of pancolitis. Patients with fulminant colitis are extremely ill with dehydration, severe abdominal pain, protracted diarrhea with bleeding, and even shock. They are at risk of developing toxic megacolon (marked dilatation of the colon due to severe inflammation) and colon rupture (perforation). Patients with fulminant colitis and toxic megacolon are treated in the hospital with potent intravenous medications. Unless they respond to treatment promptly, surgical removal of the diseased colon is necessary to prevent colon rupture.