I am also sensitive to MSM. After I took it for a month (500 mg./day), my digestion and my thyroid shut down. So much for it being non-toxic up to 10 grams/day.
Learned some interesting things out of that. I don't think it was the sulphur; I think it was the methyl groups. Seems I may be Folic acid deficient. The folate/methylation cycle is complex. Still trying to understand it.