Peritoneal dialysis: A dialysis technique that uses the patient's own body tissues inside the abdominal cavity as a filter. A plastic tube called a dialysis catheter is surgically placed through the abdominal wall, into the abdominal cavity. A special fluid is then flushed into the abdominal cavity and washed around the intestines. The intestinal walls act as a filter between this fluid and the bloodstream. By using different types of solutions, waste products and excess water can be removed from the body. This form of dialysis can be done either 'manually or by machine at home, thereby avoiding hospitalization or receiving dialysis treatment at a dialysis center.