Re: endometrial ablation and tubal question
If the Nuvaring was working, may I ask why your doctor took you off it ? (is this because of insurance ?) How old are you ?
IBS is an unlikely diagnosis since the pain was occuring cyclically with your period and goes along with heavy menstrual bleeding. Also, you said that the pain was period like cramping. I do not think that IBS pain is the same thing.
As for the acid reducers, I was under the impression that these are usually used for acid reflux and hiatal hernia or Barret's esophagus and ulcer type cases in order to reduce the damage that would be caused to the esophagus should stomach acid reflux back into the esophagus. I am not sure what these drugs do for IBS except perhaps to slow down your digestive system (acid reducers do this because your stomach needs acid in order to move things along .. as a result, proton pump inhibitors and antacids reduce the acid and keep things in the stomach longer).
If the problem is indeed in your digestive system, then an endoscopy / colonoscopy (or sigmoidoscopy) would help to actually find the cause. However, from your description of when the pain occurs (it is cyclical with your menstrual cycle), the type of pain, the fact that it goes along with heavy menstrual bleeding AND when the problem started (after your C-section), this all points to a gynecological problem.
Also, you said that your doctor found a lot of scar tissue during your lap. This may very well be co-incidental but it also may not. Your uterus is obviously not contracting properly during your menstrual cycle and this is creating the problem of cramps and excessive bleeding. The problem may very well stem from your C-section.
Endometrial ablation may be the right solution for you but you will have to do some serious consideration. For example, there is a lady on these boards that has mentioned that after her endo ablation, she had irregular bleeding but was unable to have an effective endometrial biopsy because of the scar tissue that forms in the uterus after an ablation. This means that they can no longer test for endometrial cancer if the question ever arises in the future. Doctors will not mention this as something to consider for some reason. Also, sometimes the lining grows back and you are back where you started. Do some reading on the procedure before deciding. Hopefully some other ladies will come on these boards to give you their own experience. My experience was with irregular bleeding and ovarian cysts and not with endo ablation. My irregular bleeding was because of prolonged pill use.
Although I am not a fan of hormonal birth control, I have to admit that in cases of endometriosis and pain such as yours, it does seem to be one of the few solutions barring surgery. Depending on your age, physical condition and family history, the Nuvaring may be something to reconsider. Oh and by the way, sometimes endo could be very very small, cause a lot of pain and they never find it. This means that a diagnosis of endo should not be dismissed entirely.
I hope you find the right solution for this problem and that the pain will no longer be an issue for you in the future. Take good care of yourself.