Hot tap water comes through copper pipes - it's not a great idea to drink it. Boil cold water then let it cool to lukewarm, or mix boiled with cold. I drink regular cold tap water and make sure I'm getting at least 2-2.5 L per day.

I find snacking on dried fruit really helps. I make sure I'm going for walks twice a day and that seems to keep me regular as well. Good luck - it's an awful feeling!