I've woken every morning to diarrhea for 5 days in a row. It doesn't occur throughout the day. Should I be concerned?

Diarrhea. Daytime diarrhea is usually functional, like irritible bowel whereas diarrhea in the middle of the night sounds more like an infection. 5 days is pretty acute; we usually distinguish at 2 weeks. Could be a stomach flu still or salmonella or campylobacter from some food you ate.