Are there foods we should stay away from?

You may very well find foods that disagree with you.  You might not.  I have never come across anything that caused me a problem other than sugar, especially liquid sugar.  The only food my surgeon pointed out as "best avoided" was fresh oranges.  I guess he has cleaned out a fair number of stomas that were clogged with the tough-to-chew membranes.

Or he thought the acid from citrus was too hard to handle initially

That is not what he told me.  He said it was due to blockages.

Stay strong and I would implore you to not go back to chocolates and crap. No one really talks about regain. It can happen