Does anyone know the side effects of stopping imuran (azathioprine) all at once?

Disease may flare: Imuran (azathioprine) is a non specific immunosuppressive drug used in several autoimmune diseases (i.e. Inflammatory bowel disease) and transplant rejection. It usually suppresses the formation of white blood cells. If suddenly stopped the reason it was prescribed may suddenly flare. You should discuss changing the dose with your doctor.