I would suggest before you go down the surgery route, you do something to stop your periods and see if that means that you can avoid the painful bowel issues.
Taking birth control pill packs back to back for 3-4 months then break and have a period and then back on the pills back to back again, will reduce the number of periods to 3-4 a year instead of 13.
Or a tablet called norethisterone which you take 3 times a day for as long as you want to hold off a period and if you miss a couple aaccidentally or deliberately it will trigger a period and these can be used to have some control about when you time your periods so you can avoid being on, when you hve exams, or training courses or holidays etc.
These will soon tell you if what you are experiencing pain in the bowels wise is from bleeding which would normally mean either endo or a similar condition called adenomyosis.
Plus it gives you relief from that experience and could prove a much better alternative to having surgery on the bowel.
I do have endo in the bowel as well as outside it and have had major surgery on other parts of me with endo, so I am not ready to have the bowel op though it is something i will probably need to have at some point, for the time being I have stopped my periods completely with mirena coil which lasts for 5 years.
There are other long term options which last for 3 years like arm implants and the smaller Skyla coil.
These methods don't kill off or stop endo, but they do stop the cycle of pain and cramps and swelling and bloating that comes with having a period and can make life very unpleasant.
At any event it certainly needs investigating tobe diagnosed even if you do not go throug with surgery just yet. The accredited endo centres around the UK all have endospecialist colorectal surgeons on the surgical teams and two of the types of endo that causes these bowel pains is either RV or recto-vaginal endo or sigmoid colon endo.
Normally we recommend surgery not only to diagnose endo but also to remove all existing endo where possible. The problem is that with bowel endo this can sometimes mean having a section of your bowel removed and a colostomy bag attached while the wound heals. This is a bit of an ordeal and if you can find a way to live with the bowel issues avoiding surgery as long as possible it is the much less risky of the options available to you, which is why stopping periods can be a really useful way to cope.
The accredited endocentres are listed on
and you just need to check for your most conveniently located one and take the details to your GP when you are ready to ask for a referal to the to discuss your case and get some initial tests and scans done.
They are not to check for endo as they won't always show any endo, but rather to rule out any other possible causes.
Meantime your GP can discuss and prescribe which ever method you want to try first to stop your periods so hopefully you don't have to put up with bowel pain each month now and in the future with or without surgical intervention.
If you consider the mirena coil - which has been a life line for me and many others, then it is best inserted during your lap op. it takes 4-6 months to settle and get to work then should stop your periods up to 5 years unless you have it removed earlier if for example you are wanting to start a family.
I still have bowel endo problems but nothing on the scale it used to be. It is manageable and while some trips to the loo do require 10-20 minutes of recovey afterwards by sitting still, it certainly worth it in terms of avoiding another massive op and lengthy recovery.