What Causes Foul Smelling Stools With Mucus, Bloating And Pain In Stomach?

Me and my fiance are having some stool issues.. been going on for a little under a week at the moment, but its not ceasing. We both have lactose issues and have kind of been blaming that, but being it hasn t stopped... We re just not sure. Foul smelling, kind of mucusy, both of us have a bit of abdominal discomfort and we ve been experiencing a bit more flatulence than usual... Should we stop waiting this out and just go in?