Your daughter does not need a psychiatrist. He will only prescribe antidepressants that have the side effects of suicidal thoughts. And we don't want that! Doctors think that teens, especially young teens, are not able to get endometriosis. Yet I have several friends who have had it since their first cycle (about age 12 or so). In the beginning, Endometriosis forms implants anywhere in the body, but mainly in the abdomen and pelvic area. The implants start small and usually cannot be seen except through laparoscopic surgery. As it builds though it can form cysts. Endo. causes excruciating pain, especially if it is on/near nerves.
Has your daughter been tested for celiac disease? It is a blood test. Is your daughter seeing an ob/gyn at all? or just a GI doctor.