The large intestine consists of the cecum, ascending/tranverse/descending/sigmoid colon and
usually begins in the rectum and may continue up into the colon. When inflamed, the intestinal
become red, swollen, develop ulcers and bleed. This inflammation and irritation can prevent the
intestine from absorbing enough fluid and salt from stool, leading to diarrhea.
UC is a chronic, lifelong disease with alternating periods of activity and remission. Patients may experience intense symptoms followed by varying periods of time when the symptoms seem to disappear.
The cause of ulcerative colitis is unknown, but it appears to involve dysfunction of the immune system. Protective cells normally present in the gastrointestinal lining are triggered to attack when bacteria and viruses pass through the digestive tract. In patients with ulcerative colitis, this attack continues, even when harmful substances are no longer present – leading to chronic inflammation and irritation. It is not clear whether this immune dysfunction is a cause or result of UC.
UC appears most often in people between the ages of 15 and 35, but may also occur in older or younger populations. About 500,000 Americans have UC, according to the Crohn's & Colitis Foundation of America (CCFA). Another 500,000 have Crohn's disease (CD), the other major type of IBD.
Ulcerative colitis differs from Crohn's disease in a number of ways. In patients with ulcerative colitis, only the large intestine is affected whereas CD may occur anywhere throughout the digestive tract, including the small and large intestines. Inflammation caused by UC is usually continuous, without any normal tissue appearing between inflamed areas. In CD, there may be patches of normal tissue between inflamed areas. In addition, UC affects only the inner lining of the intestine, so ulcers are not likely to break through the innermost intestinal wall layer (mucosa), as may occur in patients with CD. Inflammatory bowel diseases such as UC and Crohn's disease are sometimes confused with irritable bowel syndrome (IBS). However, IBS does not involve inflammation of the intestines, which is present in both UC and CD. Also, IBS does not include bloody diarrhea as a symptom and IBS tests reveal no abnormalities. IBS is not associated with either ulcerative colitis or Crohn's disease.
The first step in diagnosing ulcerative colitis (UC) is a visit to a physician for a medical
physical examination. Individuals will present with the following complaints: rectal bleeding,
strain to produce stools (tenesmus), repeated bouts of diarrhea then constipation, rectal
cramping, fever, malaise, nausea and vomiting, joint pains (arthralgias), and night sweats. If
have a severe bout of ulcerative colitis, they will present to the physician with fever, body
(dehydration), increased heart rate (tachycardia), and abdominal tenderness.
Patients may be asked about the extent and duration of their symptoms, any family history of inflammatory bowel disease (IBD), as well as their eating, drinking or smoking habits. Blood tests and stool samples may also be required. Blood tests can identify low red blood cell counts (anemia) and high white blood cell counts (which may indicate inflammation or infection). A stool sample analysis (fecal test) can identify bleeding or infection of the large intestine.