What Causes Persistent Pain In The Lower Abdomen?

Hey there i have had a pain in lower side of my abdomen for years i have had a laporoscopy 2-3month ago and they couldnt find anything i was getting looked at for endometreosis as my mother has had that and i have very similar symptoms also thought was ibs but it isnt i want answers there is something going on. I thought maybe could be tube blocked anythig you can tell me please. Thanks