Have you had a colonoscopy? There are medications to prevent spasms and break up gas in the intestines with IBS, are you not on any of these?
What tests have you had other than "xrays" and an MRI? An MRI isn't the best test for GI problems; at least not the colon. If the problem seems to be purely colon related, a colonscopy would be the best diagnostic test. If you have a weak rectal sphincter, and lots of stool on that side (left), your rectum would hurt; maybe even if the sphincter is normal. Maybe there are internal hemorrhoids (though those should be found on rectal exam). Have you had a flexible sigmoidoscopy? That's where they check the lower part of your colon (sigmoid colon) with a scope. And then there's the always-fun barium enema! I'd vote for the colonoscopy.
Have you gotten your problem figured out? I have had a similar experience but it's not from stress. I was out with my boyfriend the other night. We were getting all hot and heavy and I had to pee. I didn't want to break the mood so I just held it. I had two orgasms from oral sex and one from normal sex but then I had to go pee cause my stomach had such a sharp pain in it. I had a hard time going pee. It was very slow to come out and it was a lot and sharp pains accompanied.
Those pains moved to the rectum and I started having such sharp pains I could hardly walk and I could not stand up straight.
I took it easy slowly got to where I could get home. I sat on the toilet when I got home and the pains were excrutiating. I thought something was going to come out of my rectum that shouldn't. Even to pee was painful. I couldn't even bend over to pick up my shoes when I was done. I could not sit down cause It hurt so bad to sit. In the middle of the night I woke up with such a sharp pain I felt like I was giving birth out of my backside and my abdomen was still sore.
It's been two days and I am still hurting a little bit. This is not the first time this has happened and it always seems to be when I hold my urination.
What have you found? Maybe it will give me a place to start.
check out Proctalgia Fugax. May be what you have. I just had it diagnosed, there is a pill you can take under your tongue to relax the muscles.
I don't drink often this incident. One day i drink too much and the following day my rectum was paining...few days later found fressh blood....then i stopped drinking beer for 4 month...everytime i drink, the following few days i have rectum pain.....even i did not take for 8 months of time, the beer in this case.....for the past 8 month, i took probiatics 3 months and high fibre for 5 months....still the problem is not recovered......pls advice