I get pain in the groin area only at night lay down. this is the left side. If I bend my left leg the pain is reduced, with my legs straight the pain increases. I recently had surgery to remove a cancer in my rectum and part of my colon so I have less in that body area. I wondered if my ureatha on the left side was becoming trapped by my small intestine and causing the pain. It is somewhat relieved after empting my bladder but gradually comes back as I lay down and sleep. I do not get the pain during the day.