I just recently quit (3 weeks now)... Smoking has an adverse effect on Crohns, and it can lessen the impact many of the drugs have on the disease. With Ulcerative Colitis, it can have just the opposite effect. Those with UC really need to be careful if thinking about giving up tobacco, especially cold turkey. I tried quitting about 5 years back. I'd been symptom free, and thought it was a perfect opportunity. I went on nicotine patches and simply stopped smoking altogether. Now, my form of IBD is pretty rare, I've both Crohns and UC. Within days of quitting, I flared really bad, started bleeding heavily.
Gave it a week, resumed smoking, bleeding stopped within 24 hours. Took me months to recoup. This time, I did it differently, and so far, so good. I tapered off tobacco slowly.
Essentially I reduced how much I smoked on a weekly basis. Then, when I was down to 6 cigarettes a day, I stopped cold, and started using Nicotine Replacement Therapy. I've gone from 21 mg, to 14, then 7, and these last 4 days.. no nicotine of any kind. And no issues... no bleeding, other symptoms. My pain levels have increased, but that was something I anticipated. I don't know what the connection is, how the mechanics of it works, (and it seems to have no connection with nicotine itself, at least not in my case), but smoking really curbed the pain from my internal scar tissue like nothing else (I've been told I could get the same effect from MM, but it isn't an option given my line of work). Now, some might mistake my post as advocating smoking... make no mistake about it... smoking kills. However, I started smoking in hospital way back as the ONLY way (at the time) to stop my bleeding... I realize how dangerous a treatment it is.. but so are many of the things we take/do to try to fight this disease. And I personally feel no one has the right to judge our decisions, choices... we are all just trying to cope. But, if someone out there automatically thinks quitting smoking will improve everything, AND part or all of their IBD is Ulcerative Colitis in nature, they need to be warned there is a real potential for a major downturn in their symptoms... and to tread very carefully.