Endometrosis is a chronic condition in which pieces of your womb's lining attach to other organs and begin to grow.
Your cramps may seem like regular period cramps, but they can happen any time of month. You may also have cramps and pain in your low back and stomach below your belly button.
Sex that involves deep penetration may be painful. Some women have painful bowel movements. Endometriosis can make it hard to get pregnant.