Alfaman147.....I had a similar compulsion once upon a time. I was living in Newfoundland, CA. I made the mistake of getting incredibly drunk and long story short, I made a mess of myself, falling down numerous times on my left shoulder and ribs. Now, if you know anything about Newfoundland, it's basically Ireland in Canada, and it's pretty easy to tie one off down on George Street.
I was in incredible pain for 2 weeks. My ribs were killing me on my left side. I couldn't laugh or cough. I learned that lesson the hard way when I sneezed one day at the office. I had evidently pulled a lot of intercostal rib muscle from my front to my back. I was convinced I had a diaphragmatic hernia, absolutely convinced. I saw two separate nurses on the job site, both of which were very experienced in these types of injuries. Both assured me that it was almost a guarantee that I had no such protrusion because the signs and symptoms are quite obvious. It took me 4 months to recover, and this was most definitely not TMS at the time.
During my recovery, I scoured the internet looking up all kinds of hernias. At the end of my mess, I concluded it was virtually impossible that I had one. Sometimes we take things to far. My compulsion with hernias was no different than yours with prolapse. Our problems simply cannot exist given the circumstances. It's like convincing yourself you've amputated your arm after a paper cut.
The forums aren't necessarily a terrible thing provided you're not endlessly researching your issue. I have the same issue with constantly researching these things, but I'm slowly resetting my brain to shut this down. Sometimes you have to just let the discomfort wash over you then move on, kind of like when you experience a shiver.
All the best.