I too, am new to the site. It seems that a lot of people post here though. I have found some useful info over the last few weeks. Anyway, I wish both of you luck with the surgeries. I have a temp. ileostomy scheduled for 4/20, so I am ahead of you guys.
As for kidney stones, I wouldn't think there would be any impact on the kidneys because the colon is being removed. They filter blood, and removing the colon only leaves less blood for them to filter. Just speculation on my part. I would ask the doctors and make them explain why there is or is not a connection.
You see, one thing I have learned over the years is, unless you have an adequate explanation and understanding of what is going on with your body, the mind tends to work overtime finding things to worry about
, or building false understandings of what is going on.
Anyway, good luck to you both....(actually your husband, sorry)