Vomiting from Imuran

Has anything changed? Like you're now taking a higher dosage than before? Please mention this to your gasteroenterologist if you haven't already.

I would check with your doctor. Are you doing blood work?
I would get horribly nauseated if I took it in the morning so I switched to taking mine at night with dinner. If I don’t eat a full meal when I take it I do still occasionally deal with nausea.

Another thing - you should be able to split the dose in two and take them 12 hours apart which should help with the nausea, if you aren't doing that already. But check with your doctor on that.

Get your wbc checked. Usually i feel nauseated in general when my wbc drops. When my wbc drops to 2.8-3.2, i get extreme nausea. I think vitamin D helps with that. You should totally take it if you aren't already. Your body will get used to it in a few months. I started a year back and still run into occasional nausea but it's manageable. There's some info on one of my old threads https://www.healingwell.com/community/default.aspx?f=38&m=4205146#gsc.tab=0
Also ginger beer/ale was my goto for temporary relief if that helps.