I would like to know whether you are using any medication for constipation
It can distend the caecal area.Other wise IBS
and Adhesions both may lead to dilated colon and pain abdomen as you are suffering from.I guess you are admitted in hospital right now and your Doctors might be managing you conservatively.I suggest you to undergo Colonoscopy
after stabilization and it may suggest the pathology if any.
I wish you Good health soon