I had 3 major abdominal surgeries in 3 years -- cancer surgery which left me with a ventral hernia, emergency hernia/bowel blockage repair, and finally a permanent fix with a total abdominal reconstruction -- all about 1 yr apart. Each time I was able to get back to a regular exercise routine. Even being extra careful after the abdominal reconstruction during the 6 mo healing period, I was back up to a full normal workout by 8-9 mo out (doing HIT on the treadmill and seated elliptical, free weights, and balance exercises).
Unfortunately, when the gym dropped their evening and weekend hours (staffed by graduate students) I didn't keep up. I'm trying to get back into a routine now. I know what I should be doing, but I just have to make myself do it. 
Best of luck! When I had my umbilical hernia fixed years ago, my doc said that I'd be surprised how much better I would feel after the repair, and he was so right!
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