Bf cnt eat/drink anything it upsets his stomach & causes him to use the restroom constantly his bowels are watery its been a week now is it a virus.

IBS?: Need to have a bm shortly after eating anything is caused by a overactive gastro-colic reflex. This is a reflex everyone is born with but quiets down with development. People with irritable bowel syndrome frequently awaken this reflex leading to symptoms described. An elimination diet (e.g.. Low-fodmaps) might help. Medications can be prescribed as well. See your doctor. Good luck!