How long after surgery before I can do sit-ups?

I am 20 days post-op.

I wouldn't rush into crunches if I were you. You need to let the port area heal up on the inside. I'd wait at least two months, then check back with Doc.

My doc said a month out but I'm afraid to try.

I am 12 weeks post-op and I wasn't able to do crunches until about week 9. Don't rush it...you'll be able to crunch soon.

How long after surgery before I can do sit-ups?

I am 20 days post-op.

Nope you can flip your port - talk to your doctor..

My doc said 6 weeks post op.

I have been doing crunches since then, no problems. Oh, other than the problem of really hating to do crunches