Okay, It is just pain then? No poop issues? Gas issues? Others can weigh in on pain (not my issue). I have only a few recommendations:

1. Slippery Elm "tea" (inner bark) supports the mucosa of the gut. Pain might = inflammation. I take 1/2 teaspoon in hot water in the morning, first thing, but Google what might be best for her.

2. Stomach massage, to move stool and gas along. See the UK's NHS routine here: https://www.torbayandsouthdevon.nhs.uk/uploads/25773.pdf.

3. Bitter gourd. Sold at some Asian markets, either fresh or frozen. It helps me. There is a study posted to the NIH website. Google "NIH and bitter gourd." I put some in multi-veggie soups. It is definitely bitter, but I it makes a difference and I eat it often for a happy belly. If it is magical for her also, see what you can do. Maybe freeze-dry it for college and she can add it to canned soups.

4. If this genetic condition is amplified by stress, consider Cognitive Behavioral Therapy (CBT), the hypnosis route. All you do is listen to a recorded reading daily (the therapist creates a different one at the weekly session, the other days, its recording is your "homework"). Seven weeks and you are free; you can then induce the same gut benefits on your own, wherever you are, and listen to a recording again for a reboot. GI Psychology in Burke, VA. Virtual sessions. My therapist was Tina. I love that it is short course and then independence and success.

Good luck -- I am sure others will have some useful medication and other ideas.