What Causes Pain In The Back And Hip?

Had heavy bleeding, then coil removed in february, bleeding stopped and since then only bleeding a couple of days here and there. then three weeks ago, intense back pain, pain in my hip, admitted into hosptal with suspected kidney stone, ct scan .showed no stone, but a bulk on my uterus. going in to hospital for a hystoroscopy, endometrial biopsy and d and c, doctor insisting that i have a general anaesthetic, not sure if all this is going to do any good. Do you have any other suggestions of what could be wrong. I am 39 years old, 5ft 5inches, 8 stone in weight.