Steroid Induced Psychosis

I am the 45 year old mom of a 24 year old male who had a colon resection at the age of 17. He was scheduled for emergency surgery as the DR. believed him to possibly have bowel cancer. After removing 2 1/2 feet of his intestines and re-attaching the bowel to avoid a coloscopy bag we were told he had Crohn's Disease. The problems that have developed over the past 7 years are now mental issues. He admitted himself into a hospital 2 years ago were the medical professionals believed him to be suffering from psychosis (possible schizophrenia)directly related to his prescribed Crohn's medication. He refused to follow through with treatment and left the area before they could have him admitted into an institution. I am not sure what steroid he's on or meds he's taking as my hands are tied to obtain that information because of his age. Has anyone else experienced mental illness related to the medication for this disease? My son refuses to believe there is anything wrong with him but exhibits major dillusions and beleives the world is conspiring to take him down. I'm desperate for information as I don't know where to turn and when I do go knocking on doors I want all the information I can possibly get so this can't be ignored any longer. Anything is appreciated. Thanks.