crohn's inflammation

I've had a colonoscopy and bisopy done,all came back ok. ct scan, blood work, and barium test all good. Doctor said it was IBS. Wanted to put me on anti depression pills, he's only talked to me twice for 15 mins each time. How does he know if I'm stressed? Never asked me about my life. Not stressed, have a pretty good life,normal problems nothing to get all excitied about. My question is that i have dirraha like 3 to 4 times a day, extreme pain in right lower side comes and goes. I have a dull pain all the time. Also i have nausa all the time. Could i have inflammed intestine, but not show up because it's so deep in the tissue? Or do i really have IBS? Any help would be great. By the way my gallbladder taken out a year ago.