hi, I don't know if this qualifies as 'personal' experience, but as an RN, I hve taken care of patients after having colon surgery. The most helpful thing I can think of to tell you is: the patients who do best when recovering are the ones who have lots of loving support and prayers (scientific evidence show that even unknown prayers or meditation increases health outcomes). The care package you send and calls you make will do wonders!
As for medical information, there are a lot of different types/degrees of colon surgeries, the biggest risk is infection due to bowel materials. The heart murmur shouldn't impact anything (it's very common), and the MD's can conrol blood pressure with medicine, if it was a concern, they would not proceed with the surgery.
No matter what, I have seen people of all ages have colon surgeries, and they do well. It is not easy to watch a loved one go through painful events, I am sorry that you have to be so far away. I will be praying for your father!