Inflammatory bowel disease
Inflammatory bowel disease (IBD) involves chronic inflammation of all or part of your digestive tract.
Ulcerative colitis and Crohn's disease are classified as inflammatory bowel disease (IBD). These conditions share similarities but there are important differences.
Ulcerative colitis affects the inner lining of the large bowel (colon and rectum) causing it to become inflamed and develop ulcers. As a result it's unable to absorb the enough water which leads to diarrhoea. If the lining of the colon is damaged, mucus and blood often appear in stools.
Crohn's disease is the inflammation of the wall of the intestine which can include any part of the digestive system from the mouth to the anus, but most commonly affects the small bowel or first second of the large bowel. Crohn's disease causes inflammation of the full thickness of the intestinal walls and usually involves the entire bowel wall. (Ulcerative colitis affects only the lining of the bowel.)