Endometriosis occurs when the tissue that lines the uterus also grows in areas outside the uterus, according to WebMD. The tissue often grows on organs and structures in the abdominal area, such as on the ovaries, fallopian tubes, outside of the uterus, and the intestines. Common symptoms include pain, abnormal bleeding and infertility.
The clumps of tissue that grow outside the uterus are called endometrial implants, notes the Mayo Clinic. Even outside the uterus, the endometrial tissue goes through its normal cycle of thickening, breaking down and bleeding. That tissue cannot exit the body as it normally does when it grows inside the uterus. Irritation of surrounding organs sometimes occurs with endometriosis, which can cause scar tissue and binding of organs.
Pelvic pain is often the main symptom of endometriosis, says the Mayo Clinic. The pain often occurs near the menstrual cycle, but it may also occur during intercourse or while having bowel movements and urinating. Menstrual bleeding may become heavier than normal, or bleeding between periods may occur. Other possible symptoms include fatigue, diarrhea, constipation, bloating or nausea.
No cure exists for endometriosis, but treatment options are available to manage the symptoms, states WebMD. Hormone therapy helps shrink the tissue to relieve pain. Surgery is sometimes necessary to improve chances of becoming pregnant when infertility is a symptom of endometriosis.