I had to come off the imuran as it didn't agree with me. I was put on Methotrexate and had no problems with it ever.
I was on the Methotrexate with remacide and never had any problems with it. My bloods were checked regularily with the Methotrexate to check for white blood cell counts, but after a few months this was reduced to checking every time I went fot the Remacide (every 8 weeks)
I suggest you search on this forum for Methotrexate, as there have been quite a few posts on this.
Methotrexate is a chemotheraphy drug and is used in lower doses for Crohns
Excerpt follows from a quick search on web:
Methotrexate can cause side effects on liver, lungs, kidneys, and bone marrow (immune system).
Use an effective form of birth control, whether you are a man or a woman. Tell your doctor if you or your sexual partner become pregnant during treatment.
To be sure this medication is not causing harmful effects, your blood will need to be tested on a regular basis. Your kidney or liver function may also need to be tested. Do not miss any scheduled appointments.