*TMI* ahead!!!

ok ive had the runs since friday when i though i had gastro, no vomitting just nausea, was fine by yesterday only had the runs first thing in the morning, i woke at 2am this morning with the runs again, then again upon waking. although i feel fine,eating normally etc....am i contagious??? or do i just have an inbalace of bacteria in my intestines???? i am taking inner health plus tablets