MedGen

The occurrence of an immune reaction against the organism's own cells or tissues. [from HPO]

Ulcerative colitis is a chronic disorder that affects the digestive system. This condition is characterized by abnormal inflammation of the inner surface (epithelium) of the rectum and colon. The rectum and colon make up most of the length of the large intestine. The inflammation usually causes open sores (ulcers) to develop in the large intestine. Ulcerative colitis usually appears between the age of 15 and 30, although it can develop at any age. The inflammation tends to flare up multiple times throughout a person's life, which causes recurring signs and symptoms.

The most common symptoms of ulcerative colitis are cramping abdominal pain and frequent diarrhea, often with blood, pus, or mucus in the stool. Other signs and symptoms include nausea, loss of appetite, bowel urgency, fatigue, and fevers. Chronic bleeding from the inflamed and ulcerated intestinal tissue can cause a shortage of red blood cells (anemia) in some affected individuals. People with this disorder have difficulty absorbing enough fluids and nutrients from their diet and often experience weight loss. Affected children usually grow more slowly than normal. Less commonly, ulcerative colitis causes problems with the skin, joints, eyes, kidneys, or liver, which are most likely due to abnormal inflammation.

Toxic megacolon is a rare complication of ulcerative colitis that can be life-threatening. Toxic megacolon involves a widening (dilation) of the colon and an overwhelming inflammatory response. Ulcerative colitis also increases the risk of developing colon cancer, especially in people whose entire colon is inflamed and in those who have had ulcerative colitis for 8 years or more.

Ulcerative colitis is one common form of inflammatory bowel disease (IBD). Another type of IBD, Crohn's disease, also causes chronic inflammation of the intestines. Unlike ulcerative colitis, which affects only the inner surface of the large intestine, Crohn's disease can cause inflammation in any part of the digestive system, and the inflammation extends deeper into the intestinal tissue. [from MedlinePlus Genetics]

Inflammation, or an inflammatory state in the large intestine. [from HPO]

Inflammatory bowel disease is a systemic disorder comprised of two major disorders: ulcerative colitis and Crohn disease. Crohn disease can affect any part of the digestive system while ulcerative colitis is confined to the colon. Both disorders may affect sites outside of the digestive system [from SNOMEDCT_US]

A disorder resulting from an abnormality in the immune system. [from NCI]

Any abnormality in the activation of T cells, i.e. the change in morphology and behavior of a mature or immature T cell resulting from exposure to a mitogen, cytokine, chemokine, cellular ligand, or an antigen for which it is specific. [from HPO]

A hypersensitivity reaction type II disease that involves the alimentary part of gastrointestinal system. [from MONDO]

Any abnormality of the large intestine. [from HPO]

A functional anomaly of the large intestine. [from HPO]

A deviation from the normal count of T cells. [from HPO]

Underdevelopment of the colon. [from HPO]

Any abnormality in the total number of lymphocytes in the blood. [from HPO]

Any inflammatory bowel disease in which the cause of the disease is a mutation in the IL10RB gene. [from MONDO]

A developmental defect resulting in complete obliteration of the lumen of the colon. That is, there is an abnormal closure, or atresia of the tubular structure of the colon. [from HPO]