You really need to get it done. Do you really want to put off fixing something now vs dying down the road just because of anxiety?
If you don't want to get the procedure done because of anxiety, then don't - no one can tell you what to do. But don't complain about it and about your medical problems if that is your decision. I think you *know* that you need to get it done, if nothing more than to rule out causes for what you are going through.
If you are in southern Calvert or St. Mary's Co. then go to Dr. Shah (can't think of his first name). I know there are a hundred of them but he's the one in the Bean Building that deals with stomach issues. Maybe someone knows his first name... but he is great. He's not really 'personable' but he is good and he will listen to you. AND he will do an exam before he does a colonoscopy - he'll order blood tests and probably a CT scan before he does the colonoscopy.
I went through something similar (though not quite as mine had nothing to do with my menstrual cycle) and had testing and a colonoscopy. Dr. Shah was great - again, he isn't really 'friendly' but he will listen... I had a lot of fears too, and yes I know about severe anxiety - I actually take medicine for mine when it gets too bad (had a thread about driving while 'anxious' and on medicine not too long ago
) and I also have a heart murmur and other medical issues that made me fearful. That said, I never once considered NOT doing it because it was necessary to rule out any life-threatening things. Dr. Shah and the nurse assured me that I wouldn't remember a thing, and I didn't. I didn't even know it was over, didn't have any pain afterward - it was fine. My tests turned out good and the issue was due to something systemic (similar to the poster that talked about ankylosing spondylitis - I think that is systemic too) that was causing a lot of acid reflux among other things.
BTW - I am young too (31) and I know how it feels to have medical issues at such an early age. It sucks - but you have to deal with it. I don't know if you have kids or not, but mine are my driving force to be as healthy as I can be and to get things checked out/things done in order to be around for them as long as I can. Most of the time things turn out to be minor - but ignoring something or putting it off just because of anxiety is sort of silly when you think of the overall picture.