Ulcerative colitis is a disease that causes ulcers in the lining of the rectum and colon. It is one of a group of diseases called inflammatory bowel disease. Ulcers form where inflammation has killed the cells that usually line the colon.
Ulcerative colitis can happen at any age, but it usually starts between the ages of 15 and 30. It tends to run in families.
Crohn's disease causes inflammation of the digestive system. It is one of a group of diseases called inflammatory bowel disease. The disease can affect any area from the mouth to the anus. It often affects the lower part of the small intestine called the ileum.
Crohn's disease seems to run in some families. It can occur in people of all age groups but is most often diagnosed in young adults.
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.
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 diarrhoea, 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 diarrhoea, abdominal pain and cramps, weight loss, fatigue, fever, and night sweats.
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).