Well... in theory your imune system will be "modulated" and you can be more vulnerable. But, usually, although your leucocytes are in a lower level, it doesn't became too low.
In my case, I get a flu in the same rate as before. But yeast infections (skin)... became more commom.
Male, 35 (lovely family of wife and two daughters)
Diagnosed in nov/94 - Started with Prednisone, followed by Pentasa, entocort, flagyl, Imuran, Cipro, etc.
Blockage (popcorn!!) - First Surgery 2001 (no ressection)
Severe bleedind - 2003 - Stopped by 60mg of Prednisone
Stricture leading to a ressection in Dec/2008 - Second Surgery
Now on Remicade +
100 75mg Imuran + Iron (doc said i'm in remission, but I'm not sure at all)