Congrats on your twins! It may seem like alot of work especially with Crohns, but keeping an optomistic mind state WILL help!!!
I'm pregnant with my first child now... Im 22 and Ive had Crohns since I was 18. I've been lucky so far, my disease was in remission when I got pregnant and Ive felt healthier in the last 6 months then I have since being diagnosed. Im sorry to hear your not doing as well, wish there was something more we could do then give advice.
If I was in your place Id have my doctors follow me CLOSELY just to be on the safe side. Preterm birth would be a high risk for you unfortunatly... but it would be that way regardless because your carrying twins. Get as much rest as possible, dont strain to do ANYTHING. Drink as many fluids as you can stomach- water and juice are the best for your babies and will keep you well hydrated (staying hydrated will lower your risk of preterm birth and will also help with Crohns symptoms). Take your vitamins if you can.... they might constipate you after a while, if that happens you can always switch to chewable flinstones vitamins or ask your doctors about prenatal vitamins with added stool softener. All I can say about eating is eat whenever you can, and make EVERYTHING YOU EAT COUNT!!! Dont fill up on junk food or something with less nutrients if you can possibly stomach something better. Of course thats easier said then done, but at least try for your sake and your babies!
Last... if you feel AT ALL wierd or in pain anywhere dont hesitate to go to the doctor or E.R. You never know when those little pains could be more serious then they feel. I learned this during the last week- had a few braxton hicks contractions and some back pain... Considered just going to bed and hoping it would go away. My husband insisted we go to E.R. to be safe, and it turned out my cervix was soft because I was dehydrated and had been on my feet to much. So now Im on bedrest and drinking water 24/7.
Also- dont be afraid to ask for help. Turn to those who are your support system, let them know when you need help! Now is the time for you to lie back and focus on yourself and your unborn babies.
I hope you start feeling better!