Endometeriosis and abdomenal pain??

I'm 19 and was diagnosed with endometeriosis at 15. However the past 6 months i have been extremely ill and eventually met a general surgeon who took me seriously. I was told i had a touch of irritable bowel yet he is worried about other conditions but did not say what. I got two letters yestersday from his surgery. first i have to have a CT scan of my abdomen and pelvis. then the following week i must have a double contrast barium enema done? What could be wrong? is the double contrast painful getting it done?