Stepping in a little late. First I don't find your weight too off for height. I am 5'2" and when I tried before I got down to 125. That is where my CURVY body stopped losing. But my college roommate with no curves was 5'2" and 104 lbs. So it is all relative.
The hair loss should be a red flag though. The multiple periods too. A nutrionist is a must if you have IBS. My husband has Crohn's and I get to witness weekly how it hurts him when his body attacks from the inside. I know with your condition you probably eat what keeps your tummy from waging war, DH does as well. But I would keep a food diary, talk to a nutrionist. It helped DH a lot to see one and he kind of knows now what triggers his Crohn's pains.
You might have to eat more but eat better choices. You might be 110 but firm and happy. Remember 110-115 on an active body is going to look different. Sounds like maybe you have some deficiencies in vitamins/nutrients/calories and a nutritionist might be a helpful stop if you are serious about eating right. DH's was covered by our insurance since he has Crohn's so it wasn't too expensive and very helpful.
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan