Coffee used to work for me for
constipation on occasion, so I know that
coffee can do this. I have since developed a true allergy to coffee, which will cause me to have breathing problems if I drink it. Going down the coffee aisle in a supermarket will make me sneeze.
If your bowels are opening up, as in diarhea, this much then you run the risk of dehydration. And, don't forget that coffee is also a diaretic, which means that it will take water away from your body.