I'm surprised no one mentioned me, the one, the only, MSB!
Nah, in all seriousness, I have very severe crohns disease. Mine went down a route that has made me quite the medical marvel for the doctors. It began fistulising, and the tracts look like spagetti junction down there, so they will probably never heal. They fill up and become giant abscesses, I think my record was a few huge syringe's worth. I was colostomied to give that part of the colon a rest, but it was all just one big trick because they knew full well it would likely never get reversed. I've been hospitalised at least 10-20 times with this now and i've only been diagnosed for about 5 years. I went undiagnosed and had stomach pain for years, and my wanker doctors kept saying it was IBS goodbye.
When it's not being treated well and i'm in flare my eyes feel very puffy, and I absorb less than 50% of what I eat. At one point I was eating at least 5000 calories a day and I dropped down to 11 stone. The doctors advise is to keep a buffer of extra weight ready for the next time I can't absorb anything, but I obviously don't want to do that. It's a bit confusing as to when I can and can't get away with eating certain foods. Your friend will probably spend most of their life being a lot tider and worn out than most people, and travel to certain countries will be off limits. I'd recommend she gets put straight on infliximab. In the UK they tend to hold it back because it is so expensive, instead prefering to give shitty drugs like azathioprine, 6-mp, and steroids (not the good ones). Also, look into LDN, that's what i'm on and it seems OK. O, and tell her that taking a good multivitimin and lots of fish oil is very helpful.
Any way, i'm guessing the main thing you want to know is how drugs will affect your friend. I can only really comment on my experiences with various substances, whether they carry across for anyone else I don't know. I've been meaning to put this write up out there for a while because there isn't much info out there for people with crohns at the minute:
-MDMA = Fine. Doesn't cause flares. If anything just leaves me feeling alright apart from the come down. If, however, i'm already in a flare it's pretty bad news. Make sure you're in good health if you're going to take ecstasy and you have crohn's, and it should treat you well. It is quite a mild amphetamine by all accounts. My come ups are totally unpredictable. Sometimes it can take me twice as long as everyone else, sometimes I can begin feeling it in 10-15 minutes and be fully up in under 30. Usually it lasts well beyond anyone else, I can be up up for upto an extra hour.
-Weed = Good. Makes me feel better, as long as I smoke it straight. If I stop smoking for ages, abscesses form more rapidly and I slide into flare. It's also good for keeping up appetite too (obviously). Smoke too much, and you get the obvious weed user symptoms of being a lazy bastard.
-Tobacco = Terrible. Probably responsible for a lot of the trouble i've had over the years. Since I quit that everything has gotten much better. Tell her to stop this immediately and it will pay off well.
-Nicotine Gum/replacements = Bad. Almost as bad as tobacco. Really really hurt my stomach. If your friend is going to quit then she should just put down the fags and do it. The anger will pass by day 5, and the strong cravings will be almost gone after 3-4 weeks, apart from the cravings that stay.
-Mushrooms = Poor absorbtion, can't really tell. Had the appropriate effect, but made me sick as a dog and hurt my stomach.
-Ketamine = Quite bad. Sometimes I can get away with bashing a little bit, most times it will put me into a flare for a day or two afterward, where I can't really eat while it gets better.
-Opiates = OK in moderation. Don't do too many or you'll get the normal constipation everyone gets, but worse. I once went almost 2 weeks without going to the toilet once. If you're flaring a little bit of opiates will give you a break from running to the bathroom constantly but it's a fine balance. Don't let the doctors get your friend hooked on tramadol either, because that's their first port of call with stronger pain killers. Also, tell her never EVER take NSAIDs (Ibruprofen, diclofenac etc.), they are instant flare territory.
-Benzos = Up and down, weird and unpredictable. They can result in my stomach feeling like shit the day after, they can result in me waking up and doing the biggest dump ever, or I can be normal. They are pretty much like certain bad foods I can eat on somedays and not on others.
-Caffeine = Alright if i'm not in flare. Good to get things going, like normal people. It takes some aclimatisation to get used to. Inititally it will give me belly aches if I haven't been drinking it for ages, but then after a few days it settles down. Coffee is the only thing that gets me up and going.
-Alcohol = Quite bad, to the point that I generally won't drink. The day after my stomach aches and I go to the toilet dozens of times.
-Coke = Never tried.
-Mephedrone and phet = Lots of shitting. Lots and lots of shitting. The day after my bowel feels unsteady and I can't trust farts.
-2CB = Fine. Shitting on come up, but otherwise little to no consequences the day after.
There aren't many negative interactions with recreational drugs and the medicines they give you for crohns. Obviously certain party drugs will keep you up and weaken your immune system, and if your immune system is already weakened by the medicine, then you're almost certain to get a cold after a big night out. Taking drugs with corticosteroids isn't brilliant. Apart from weed I keep almost all drug use down to once or twice a year, so I try not to push my luck. When I was drinking every day my condition just worsened.
Tell your friend it's not the end of the world. When she goes to hospital meetings and clinic appointments she's going to be bombarded with horrible outcomes. In all likelyhood she won't have that bad of an outcome. She might have a major operation or two, and she will probably be medicated for the rest of her life, and have bad years and stuff, but it's fine. I don't bother with support groups because I just get on with it and largely pretend I don't have this disease, but some people find that helpful. Staying fit, healthy, and active is key. Like it is with most people I guess.