Most water causes gut symptoms? Anyone experience this?

Been suffering from GI issues since I was a kid. One thing I still can't figure out in my early 30s is... why does most water cause me brainfog and disturbed bowel movements? The only brands that don't cause any issues for me is Fiji, Evian, and Mountain Valley. If I drink tap water, "filtered tap water" or more of the main stream bottled waters like Polsnd Spring, Deer Park etc, I get noticeable brain fog and disturbed bowel movements (like constipation). Has this ever happened to anyone? Why does it happen? Please help!!