I was diagnosed with Fibromyalgia in 2006. I needed to loose weight for a bridesmaid's dress recently and I went on a liquid diet. Turns out the shakes I was drinking were gluten-free. I started feeling amazing, I had more energy, I wasn't getting the IBS symptoms associated with FMS, and I was loosing weight. (I had lost 60 lbs. before and I now remember the liquid I was drinking then was gluten-free) After the wedding I started eating normal food again and I was puking, intense pain was back, and I was exhausted. I stumbled across and article about people often being diagnosed with FMS when they really have or also have a gluten-intolerance or Celiac. I spoke with my doctor and I had to return to a gluten diet for 5 weeks. It was horrible but I recently took the test and am back to being gluten free. The test came back negative but while I went back to gluten a rash broke out over my body so I had a biopsy of the rash done this past Monday. It looks like the blood test was wrong.
Anyway, the point I was getting to was that FMS and Gluten-Intolerances seem to mask or complicate the other. I still believe I have FMS because the tender points don't go away. Maybe after a few months of strict gluten-free I'll find I don't have FMS after all but I can definitely say that my FMS symptoms are crazy worse with gluten. Also, after two weeks gluten-free my clothes are looser again.