interesting; i was having what i thought was this exact problem. they even verified the cysts via very expensive ultrasounds! however, when i went to the OB, he did not think it was cysts causing my pain, he thought it was irritable bowel syndrome.
basically, it sounded just like you; i would all of a sudden out of nowhere have EXCRUCIATING pain, WORSE than labor, and it would last a full hour, and then it would just go away. sometimes it would make my abdomen sore the next day as if i stressed the muscles or something :P
a heating pad works wonders. and taking ibuprofen as soon as you feel it coming on.... but heres my story..
when he said that, it all made sense, because i thought i had that when i was in high school/college. basically, your bowel habits dont make sense really, they arent regular by any means, and they can vary from diarhea (especially if you get nervous, anxious or stressed) to constipation (hard stools painful to pas)... or just simply not going, then "making up for it" the next day or something. also going along with this is gas pain, especially with certain foods etc. some symptoms are different for different people too, so you can check online for other symptoms.
my doctor then told me (not the OB; he prescribed something which i looked up and decided not to take) that people who eat 2 yogurts a day with live active cultures had their symptoms disappear until they stopped eating the yogurts. there are several brands of yogurt you can try, but yoplait is the most common. it seems to work for me, as long as im eating my yogurt, i have NOT had the horrible, fetal position cramping.
anyway, i hope this works for you, if not, just ask for a second opinion or a third if you have to. i want you to know that IBS isnt a HUGE deal; its not connected with any major concerns like cancer or anything. its just something you might have to deal with, work with, and make sure you eat healthy. greasy foods can cause and aggrivate symptoms so try to avoid that. :) for me soda also bothers. and theres nothing healthy about either greasy food or soda, so stopping eating/drinking those is a great idea.
anyway. good luck