I had periods like this when I was younger--from the first time I got my period until my first child at the tender age of 32. My problem was due to endometriosis. My mother never understood what I was going through until she finally saw it one day and rushed me off to the emergency room which was very embarrassing at 16. Almost the same story by the ER doc that your friend got: "It's your period. Take some Midol. Some girls are like this." At around 18/19 I got some relief from the pain and diarrhea from a prescription medication with a narcotic component to it (gynecologist prescribed) but then I was basically looped for a day .. and then constipated afterward. When I was in college, he prescribed birth control pills which did stop the horrendous periods but caused cysts in my breasts and after the 5th surgery for those, I packed the pill away. I was told I couldn't never get pregnant because of the endometriosis so I did not use birth control for years! The doc's exact words are, "You'll never get pregnant. You have endometriosis."
I wish I would've known about TCM/acupuncture then as I do now because I think it would've worked wonders for me. What cured me, however, was the birth of my first. I never had any periods again remotely like those before getting pregnant. Labor was pretty much the same feeling as those periods, however, complete with the emotional signposts, the contractions coming closer together, diarrhea, nausea, etc.
I would also encourage your friend to see a TCM practitioner and also to see if she can find a midwife or holistically-minded physician to work with her. I certainly don't recommend using pregnancy as a cure for possible endometriosis, however!