G.♣.
I've only ever had 2 c-sections, but I've never heard of IBS being common after c-section.
I would call your doctor's office in the morning. The nurse will ask you more questions to help determine whether this is something you can handle on your own (with change of diet), whether or not you need a prescription, or if maybe you should be seen.
Definitely give your OB a call. They've heard it all before!