In reply to sarmarks:
I'd strongly advise against doing any climbing for 3 months or so...
You do need to get up and walking around the house pretty quickly but may well feel fairly knackered for the first week or two. Once the clips/stitches are out (if indeed they need to come out) at 1-2 weeks start getting gently back in to walking and gentle rehab exercises, but generally avoid lifting (i.e causing strong sustained or explosive abdo muscle work) for a month. Walking over uneven ground will bring back core strength and help general post-op wobbliness. It's a pretty significant incision and needs time to heal properly. Most folk who have laparotomies aren't young climbers of course, but physios are often pretty clued up about exercise and so pick their brains when you are on the ward.
Good luck with the recovery - slow and steady wins the race!
Cheers
b