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.\n\nThe 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.\n\nToxic 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.\n\nUlcerative 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.

A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

Status epilepticus is a type of prolonged seizure resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms which lead to abnormally prolonged seizures (after time point t1). It is a condition that can have long-term consequences (after time point t2), including neuronal death, neuronal injury, and alteration of neuronal networks, depending on the type and duration of seizures.

Failure of the immune system to protect the body adequately from infection, due to the absence or insufficiency of some component process or substance.

Increased susceptibility to infections.

A disorder of the brain caused by an infectious agent that presents with fever, headache, and an altered level of consciousness. There may also be focal or multifocal neurologic deficits, and focal or generalized seizure activity.

An abnormally decreased level of immunoglobulin in blood.

A reduced proportion of central memory CD4-positive, alpha-beta memory T cells compared to the total number of T cells in the blood. These cells have the phenotype of CCR7-positive, CD127-positive, CD45RA-negative, CD45RO-positive, and CD25-negative.