Redundant sigmoid colon-doctors don't seem to know what to do. Why?

[Sookie8]

For 12 years I have had the quality of my life ruined by this nagging pain/pressure in my rectum.  I went to several gastrointerologists and they said I was constipated and I had a defecgram test.  They sent me to a uro-gynocologist who eventually performed a rectocele repair, this did nothing.  Then they did another defecgram and said my vagina was pushing on my rectum, so another surgery to strap up my vagina, no change, no relief.  Then they did another defecgram and sent me for an enterocele repair, this did nothing.  I have bloating, my belly gets stretched and terribly sensitive to the touch.  I have relieved constipation through the use of magnesium and Linzess. However, I always feel that I have incomplete bowel movements and the pressure in my rectum feels like a fist is pushing down/up.  Hurts so bad I can not do the things I want, like walk the dog, garden, etc. I also have problems getting to work and trying to act like nothing is wrong, but the discomfort is horrible and by the end of the day I am exhausted from it.  Now after another colonoscopy, I am told I have redundant sigmoid colon.  Once again they want me to have another defecgram.  My GI doctor says that surgery may not help me as she does not understand why I have the rectal pain.  The trapped gas, bloating, incomplete bowel movement feelings stops me from making too many plans in the future, as I never know how I will feel that day.  It is also not the easier topic to explain to friends, co-workers and family.  I will probably go for the fourth defecgram, but I am at my wits end.  Any suggestions?