ab crunches-- hernia??

I do ligh****er aerobics class 3-4 times a week and try to do some form of exercise  (swim, treadmill, bicycle, etc) for one hour 5-6 days a week, including the swim class.   I'm down to 278 from an all time high of 397.  When I had my WLS, the surgeon discovered a strangulated hernia (intestine twisted and poked through the muscle wall).  I had no idea I even had one. Now, 3+ months after the WLS,  I've really been working on abs lately, doing crunches in the pool.  Today and yesterday my stomach really hurt.  Is it possible to re-injure or get a hernai from crunches, or is it just my poor, flabby stomach muscles aching from the crunches?  How can I tell the difference?

after re-reading that, I should have said the surgeon fixed the hernia while he was in there for the WLS.

I have an incisional hernia that only shows up when I do crunch type movements. First time it started hurting I thought the same thing, I had just worked my abs too hard and they were cramping. Nope. I don’t seem to have the hernia issues if I stay with leg raises and other non crunch type movements.