Do you think the curry night kicked it off? Or something more recent?
It was food poisoning from something I ate on the 23rd, so the curry was not to blame. Us crohnies are more susceptible to contaminated food but I must admit this is my worst reaction by far. I was so close to going to A&E on Xmas Eve, only the lack of an abnormally fast heart rate kept me away.
I've asked him - he's unforthcoming 
I've also just found out he's been "borrowing" his mum's ibuprofen to ease the pain - which I'm told is a "No-No" for crohnes?
Please don't think I've no sympathy for him - but he's an adult, and capable of making his own mistakes.
The most I can do is recommend a course of action, and visit him in hospital <rolls eyes>
NSAIDs like ibuprofen can cause irritation of the stomach and bowel lining so yes it is not good for those of us with crohns. I have been popping the co-codamol like smarties the past few days, it's the only thing that takes the edge off without going to the stronger opiates such as vicadin or oxytocin off which you would require weaning as they are pretty addictive.
Is he taking mesalazine (Pentasa)? If so the side effects can include; weight-gain, foggy brain, loss of energy and reduced sex drive. The weight gain is a positive sign as it means the drug is working and the body is using less energy creating white-blood cells to attack the intestine, the latter side-effect can be a touchy subject especially if it is affecting any relationship he is/was in. Could be why he is reluctant to open up? Another reason people with crohn's don't open up with others is because they dont feel that they would understand what they are going through. I am not saying you dont or dont care but if that is his perception he might be bottling things up instead.