My Husband Is Having Severe Pain In His Left Side/abdomen.

My husband is having severe pain in his left side/abdomen. He just had several tests performed, one being a CT scan, and the gastroenterologist said he has a hiatal hernia among other things, but didn't see anything on the tests too serious. He does have IBS ongoing, and constantly takes pain medication. He doesn't want to go to the ER, but I just don't know what to do for him.