Colonoscopy while pregnant

Is it possible ? My doctor doesn't want to help me, because he said I'm pregnant but my ob said she's okay with it, but I need his referral, I'm so frustrated because I'm in pain while he's at home all happy and okay idk what to do where to go I have bleeding when I go to the bathroom n I have cramps For those of you wondering as to why I really need one, this isn't normal n I can't go like this for another 5 months that's crazy I can't even go out without having to go to the bathroom every 30-40 minutes has anyone had a colonoscopy and the baby turn out fine ? I'm 17w1 day