Ulcerative colitis explained

Ulcerative colitis is an inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis., a group of conditions that includes both ulcerative colitis and Crohn's disease.

The exact cause of ulcerative colitis is not yet known, but it probably results from the influence of environmental factors on the lining of the intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. in genetically-susceptible people.

The major problem in inflammatory bowel diseases is inflammationThe body’s response to injury. within the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus.. In ulcerative colitis the inflammationThe body’s response to injury. affects only the colonThe large intestine. (the large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus.) and rectum. Only the inner surface of the large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. wall is affected, not the deeper layers.

The exact cause of ulcerative colitis is not yet known, but it probably results from the influence of environmental factors on the lining of the intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. in genetically-susceptible people.

Symptoms of ulcerative colitis vary from person to person and often include abdominal pain and diarrhoeaWhen bowel evacuation happens more often than usual, or where the faeces are abnormally liquid.. Some people have a mild version and may not feel unwell. Others have moderate or severe forms of the disease, resulting in more symptoms. They may generally feel unwell. In some people, there can be periods of good health interrupted by flare-upsTerm to describe episodes when the symptoms of a condition worsen..

Classification of ulcerative colitis

Ulcerative colitis is classified according to the extent of inflammationThe body’s response to injury.. It always affects the rectum and extends from here back along the intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. to a varying degree:

  • Ulcerative proctitis affects only the rectum
  • Proctosigmoiditis involves the rectum and the part of the large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. closest to the rectum called the sigmoid colonThe large intestine.
  • Limited or distal colitisType of ulcerative colitis that affects only the left side of the large intestine. only affects the left side of the large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus.
  • Pancolitis affects the entire large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus..

The type and severity of symptoms depend on which parts and how much of the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus. is affected. People who have inflammationThe body’s response to injury. in the rectum and the part of the large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. closest to it may have milder problems than others who have more inflammationThe body’s response to injury. in the large intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus..