I was on 6-mp for years. This was 15 years ago so things,I'm sure ( I hope ) have changed but, as cinmin1985 pointed out, it does suppress the immune system and consequently you are more susceptible to infection and illness. What is a possible link is that with other immunotherapies, there is a direct risk of leukemia. I remember that from when I started Remicade treatments. That was one of the risks associated. I'm surprised that the doctors haven't said anything.
I'll send some positive thoughts your way and if I can help further, please don't hesitate...
Johanna
I was on 6mp when i was 16 ish.... and it shut down my immune system. i remember looking at this site... webmd to see side effects of the med.... and i just went back to it and found some info for you..... hope its helpful..
http://www.webmd.com/ibd-crohns-disease/crohns-disease/crohns-disease-treatment?page=10 3rd paragraph. i think..... gina