First off all confirm that the blunt wraps are actually made of tobacco. If they are they will cancel out the cannabids found in pot that would prevent damage to the lungs, as well as greatly reduce or even cancel out the healing properties to the gut. If you are going to use pot for treatment and wish to do so by smoking it switch to papers.
I disagree greatly with littlefreebird regarding it being suitable for treatment. I personally am a firm believe in using cannabis to treat IBD. After eating it and a vaporiser, rolling a joint without tobacco is the safest way to consume it. Feeling light headed and high is a far better side effect than massive depression caused by pred.
PM an MOD here, and ask for access to the medical marijuana forum over in the Treatment section. Lots of information there, or you can PM me if you have specific questions.
And the majority of people that I know who smoke pot won't touch tobacco.