Smoking has a very negative effective when you have crohns. It totally aggravates the disease. On the other hand uclerative colitis, another IBD problem is not aggravated by smoking. Some people with UC use nictoine patches because it helps control the disease. I have read over and over again how detrimental smoking is when you have crohns. It wrecks havoc on your intestines. It's the single worse thing you can do with crohns. It's also one of the best things you can give up to help keep the disease under control. I'm a smoker and I'm in the process of quitting. If it helps to keep me out of an operating room, which I believe it will then it's worth it. If cancer isn't enough to scare you then be scared by the crohns. Just something to think about.