1.) Cystocele - When the bladder drops from its normal place into the vagina...
2.) Enterocele - When the intestine bulges into the upper vagina...
3.) Rectocele - When the rectum bulges into or out of the vagina...
4.) Uterine Prolapse - When the uterus drops down into the vagina...
http://www.universityobgyn.com/pelvic.htm#Rectocele