Stage IV endometriosis is the last and most severe stage of endometriosis, states Healthline. Stage IV endometriosis indicates the existence of solid tumors in the space between the back wall of the uterus and the rectum.
Tumors caused by stage IV endometriosis can measure up to 5 or 6 centimeters in diameter, and infertility is often a complication of stage IV endometriosis, states the American Society for Reproductive Medicine. According to Healthline, endometriosis is a condition in which part of the uterus, the endometrium, starts growing outside of the uterus. The American Society for Reproductive Medicine categorizes the severity of the condition according to four different stages: minimal, mild, moderate and severe.
Diagnosis of the state depends on the amount, location, size and depth of the endometrial growths, states Johns Hopkins Medicine. When making a diagnosis, doctors analyze how much the endometrial implants have spread, the extent of blockage in the fallopian tubes, the condition of pelvic adhesions and how other pelvic structures have been affected. Although the stage of endometriosis depends on the condition's level of severity, the level of severity is not always indicative of the amount of pain caused by the condition.
Endometriosis may be asymptomatic, yet symptoms can include pelvic and lower back pain, pain after intercourse, pain in the lower abdomen and painful periods, reports Healthline.