In reply to Carpe Diem:
I suffered this indignity twice last year. Each time, I had a laparotomy and a small bit removed. I got back on the bike after 6 wks but spent the first month just bumbling around, 15mpm on the flat and no hills of any consequence. I did have a bit of tummy pain after the first ride after my second surgery, so i left it a week before trying again. No other probs.
For me, the biggest issue was weight loss, i lost 8kg each time, which has taken 5 months to regain. That has set me back a bit in pre-season 'training'.
Yoga has been good for regaining core strength, i do Hatha Flow once a week. I restarted after 6wks but again, being really careful - I used to miss a third of the positions. After 4 or 5 months, I am pretty much doing everything.
I started climbing again after 8wks. Doing long stretches to slopers was the worst bit, along with dynos.
Good luck with the recovery. I hope you don't suffer complications and have to go through it all over again