Hi, I understand your concern. If she required surgery she must have had a higher stage of the disease. However, was she prescribed any drugs like a progesterone injection to help control flare up? The pain may be due to adhesions that are common in this case. However if she is having acute and severe pain, intestinal obstruction needs to be ruled out. Check for any swelling of the stomach and ask her if she is not able to pass gases. If these are present you will need to see the doctor immediately. Other causes of pain may be a twist or rupture of a chocolate cyst of ovary formed due to endometriosis, or recurrence of endometriosis. Try hot compresses to sooth the pain. Pain killers like aspirin are not advocated under such circumstances unless the patient is seen by a doctor and acute conditions like above are ruled out. Your doctor will surely be able to help you. I suggest that you consult your gynecologist as well as a surgeon for opinion as the cause may lie in the intestines or other organs. Hope this was able to help you. I am a mother and understand your concern. She will be all right soon. Wish you good luck and take care.