Endometriosis is a disease that includes patches of endometrial tissue growing outside of the uterus. This tissue is normally found only in the uterine lining. The growth is usually confined to the abdominal cavity lining or the surfaces of the abdominal organs and it usually adheres to the ovaries and ligaments supporting the uterus. In fewer instances, it may be found adhering to the outer surface of the small and large intestines, the bladder, the vagina, the ureters, surgical scars in the abdomen, or chest cavity lining. In rare instances, it is found in the lungs (Merck, 2000, Ch. 237).
This endometrial tissue may bleed during the menstrual period, responding to the hormones that the uterus responds to. This bleeding may cause cramps, pain, irritation and scar tissue. Endometriosis may result in pelvic pain, menstrual irregularities, and infertility. In some cases the pain is severe with only slight progression of the disease and in other severe cases, there may be no symptoms. Pain during menstruation from endometriosis may not occur until the disease has been present for several years. In some cases pain may be experienced during sexual intercourse prior or during menstruation. When the tissue is attached to the large intestine or bladder, there may be abdominal swelling, lower abdominal pain during urination, painful bowel movements, and rectal bleeding during menstruation. When the tissue attaches to an ovary or structure nearby, a blood-filled mass may form (endometrioma); when this ruptures or leaks, it results in sharp and sudden abdominal pain. Progression of the disease results in adhesions or fibrous bands that connect structures that are usually not connected. At this point the endometrial tissue and the adhesions may interfere with organ functions (Merck, 2000, Ch. 237).
The cause of this disease is not known. It is thought that cells from the uterus lining might move outside the uterus and grow,...