Crohn's or just a bad cause of IBS?

I've been suffering from severe abdominal pain and intestinal bleeding which is usually accompanied by dizzyness and slight fever for about a year and a half now and every doctor I go to says well it sounds like you have Crohn's or UC but blood tests come back negative and colonoscopy confirmed nothing as well, other than that I have lesions on my intestines that the bleeding comes from. I've cut out meat, dairy and eggs from my diet and it helps most of the time other than the odd flare up. The conclusion at the end is always IBS but I don't have constipation or diarrhea, I do go to the bathroom on average 3-4 times a day though.
Oh and pain is severe enough that when I go to the hospital with bleeding they offer me morphine.... this can't be IBS can it?