I have been having trouble with Crohn's-related uveitis for about five months now (excessive floaters and flashes in vision) and I know that it can be a problem for a lot of people with Crohn's. However, I also had an issue with eyelid inflammation a couple months back that I do not think was related to either the uveitis or the Crohn's. It is called belpharitis and can be either chronic or acute, depending on the cause, but it is often just the result of some mild irritation. It can be pretty painful and can cause a good deal of inflammation and redness in either one or both of your eyelids (for me, it felt like there was grain of sand under my eyelid). I struggled with it for a few days and considered going in to see a doctor about it, but I eventually started treating it with a warm compress and it was almost completely gone within a day. If you are worried about the problem not being severe enough to take to your doctor, I would definitely try that first.
Just take a damp washcloth and microwave it for 20-30 seconds (make it as warm as you can take). Then hold it over your eye for about five minutes and gently wipe your eyelid with the corner of the cloth (don't rub your eyelid, as this could make the problem worse). Do this a few times a day. I did it as often as I could since it felt a little better each time. If this doesn't help, I would consider taking the situation to a doctor.
I am a little worried about the pain you are experiencing with bowel movements, though. That's definitely something you should monitor closely. If it is severe enough or if it worsens, I would suggest talking to a doctor. There is a chance your medications are not working as well as they were and your doctor may consider making some adjustments. Better safe than sorry.