The large vein that carries blood from the intestines and spleen to the liver.

The number of cases of a disease present in a specified population at a given time.

A chronic liver disease that slowly destroys the bile ducts in the liver, preventing the release of bile. Long-term irritation of the liver may cause scarring and cirrhosis in later stages of the disease.

Irritation, scarring, and narrowing of the bile ducts inside and outside the liver. Bile builds up in the liver and may damage its cells. Many people with this condition also have ulcerative colitis.

Short episodes of intense pain in the rectum. It is caused by muscle spasms around the anus.

Irritation of the rectum.

A doctor who specializes in disorders of the anus and rectum.

A short, rigid metal tube used to look into the rectum and anus.

The prediction of the course and end of a disease and the estimate of recovery.

Medicines that cause muscles in the gastrointestinal tract to move food. Examples are bethanechol and metoclopramide. (Brand names: Duvoid, Reglan.)