What makes you say "it's not likely to be this anyway"? Your symptoms sound very much like endometriosis so I wouldn't discount it just yet.
It's a common misconception for doctors to believe that endo causes pain ONLY with our periods and that a small amount of disease is equal to a small amount of pain. This is not true for everyone with endo. We all experience endo pain differently. Some of us have very small amounts of endo with crippling pain. Others have severe Stage IV endo with no pain. The amount of disease has no correlation to the severity of the pain it causes.
Another item of note is that endo pain isn't necessarily always cyclical. I have been living with endometriosis for nearly 20 years. Before I had surgery with an endo specialist my pain had progressed to 24/7, 365 day a year pain with an increase in severity during menses.
Endometriosis is known to be responsible for pain, scarring and adhesion formation. Unfortunately the medical professional is sorely lacking in their skill and knowledge when it comes to endo. I can't tell you how many women I've met over the years who were told the doc saw minimal disease or none at all, who then followed up with another surgery with an endo specialist only to be told they had severe disease that their hometown docs had missed.
You may want to give consideration to a consultation with one of the well known endo specialists. I wouldn't be the least surprised to have them tell you they think endo is indeed a factor in your pain and adhesions.