Ulcerative colitis

Ulcerative colitis

Ulcerative colitis is a form of IBD involving inflammation of the colon (large intestine) and rectum (final section of the colon, before the anus). Unlike Crohn’s disease, where inflammation occurs throughout the entire width of the bowel wall, ulcerative colitis is limited to the innermost (mucosal) layer of the digestive tract. The inflammation typically causes open sores (ulcers) to form, resulting in bleeding and increased production of intestinal mucus.


Ulcerative colitis can present with various symptoms, including:

  • Abdominal pain
  • Diarrhea
  • Rectal bleeding
  • Urgent need to defecate
  • Weight loss
  • Fatigue
  • Passing mucus or pus


The disease can be broken down into different types, depending on the areas that are affected:

  • Proctitis: disease activity is limited to the rectum (i.e., the final segment of the large intestine).
  • Proctosigmoiditis: disease activity affects the rectum and the sigmoid colon (section of bowel before the rectum).
  • Left-sided (distal) colitis: disease activity is limited to the left side of the colon.
  • Pancolitis: disease activity throughout the entire colon.
View pictures of normal gut and Ulcerative colitis (Warning: medical images)


Crohn’s disease
Fatigue and IBD