Suggest Treatment For Diarrhea And Dry Heaves

My husband woke 12 hrs. ago with dirreah & dry heaves......after dozing & running to bathroom for 6 hrs. he said he felt like he had a hang-over, altho he hasn t had anything to drink. He did eat 4 pcs. of bread with peanutbutter & banana on them, 2 pcs. choc. candy & a sm. chicken pot pie between 6-12. If this isn t the flu what else could it be???