I've been a smoker since the age of 14...I would quit each yr for about
6 or so months then start again (thought I'd be doing good by giving my body a break from smoking) the only CD symptoms I had were the perianal crohn's skin tags which all docs told me were simply hemmies, I thought it strange cuz I never got constipated and always had one nice normal and easy poop everyday (the tags would come and go on their own so since I had never heard of CD when I was a teen I thought the docs must be right)...
When I became pregnant with my first baby, I quit smoking in the second month of pregnancy, had a perfect pregnancy, although the anal tags were pretty big especially by the time delivery came, even the OB saw my anal tags and commented about what nasty hemmies I had but she would just cut away from them (episiotomy) Shortly after having my baby I started smoking again (was under alot of emotional stress)....a yr and a half went by and then all the sudden the tags became huge and painful and started oozing a little, and I started noticing that I was having to poop more than once a day (they were still formed and all normal looking), my GP sent me in for an emergency hemerrhoidectomy where they banded them and things did not get any better after that (of course cuz they were not, nor ever hemmies, but instead perianal crohn's skin tags) then all hell broke loose (this all happend within a month and a half)...D, blood, mucous, umbarable anal pain, tons of urgency and frequency) had to fill the tub with water to poop cuz of the pain from my anus.
about 11 yrs into my CD I decided to quit smoking, big mistake for ME, so I started again after 3 yrs of total hell (yet again) and along with the other changes I made things got somewhat better.
Pregnancy (even with the first baby) hormones are linked to CD same with birth control pills (which I was also on at age of 15, that's probably when the anal skin tags started to appear) and smoking (and I strongly believe STRESS) all have factors with crohn's.