Ulcerative colitis (UC) is a disease marked by inflammation of the lining of the colon and rectum, together known as the large intestine. This inflammation causes irritation in the lining of the large intestine which leads to the symptoms of UC.
Though UC always affects the lowest part of the large intestine (the rectum), in some patients it can be present throughout the entire colon. UC belongs to a group of diseases called inflammatory bowel diseases which also includes Crohn's disease (CD). Though it was once thought that UC and CD were two different diseases, as many as 10% of patients may have features of both diseases and this is called IBD-U (IBD-Unclassified). It is important to note that inflammatory bowel disease (IBD) is different from irritable bowel syndrome (IBS).
The symptoms of UC depend on the severity of inflammation and the amount of the colon that is affected by the disease.In patients with mild to moderate inflammation, symptoms can include:
mild abdominal cramping,
stool urgency, andtenesmus (discomfort and the feeling that you have not completely emptied your rectum after a bowel movement).
When more severe inflammation is present, patients often develop:
severe abdominal pain,
loss of appetite or growth retardation (in children and adolescents with UC).
Individuals with moderate or severe inflammation may also have to wake up at night to have bowel movements and may lose control of bowel movements.
Some of the symptoms of UC may be non-specific and could be caused by other diseases such as Crohn's disease, irritable bowel syndrome, or infection. Your doctor can help determine the cause of your symptoms and should be consulted should you experience a significant change in your symptoms.
Your doctor will usually suspect the diagnosis of UC based on your symptoms, but confirmation of the diagnosis requires testing.
Blood work is often checked to look for markers of inflammation or anemia (low blood counts), though these tests can be normal in patients with mild disease.
Tests of your stool to look for evidence of an intestinal infection are often obtained.
Radiologic images including x-rays and CT scans are usually not recommended but may be performed.
All patients with symptoms consistent with UC should have a colonoscopy or flexible sigmoidoscopy to confirm the diagnosis, assuming that they are healthy enough to undergo the procedure. During this procedure, your gastroenterologist will be able to directly examine the lining of your colon and rectum to look for evidence of inflammation and take small biopsies to be examined under a microscope to look for the cause of the inflammation.
The way in which patients get UC is still poorly understood.
Causes may include an interaction between:
the unique genetic makeup of an individual,environmental factors, anda patient's specific immune system that triggers the disease.