Skyhaven:
You described IBS perfectly. Mine is of the spastic type. The pain is the most severe pain I have ever experienced, and I have had pain before due to accidents, etc. The spasms are so severe that I can't stand up and I feel like I am on fire. Only using the bathroom will relieve this - whether it be diarrhea or not.
I am taking antidepressants to control the pain receptors - it does lessen the amount of attacks but I still get them.