Hi, and thanks for your medical question on eHealth forum!
Diarrhea is also a sign of labor. However, it can also be due to something you ate. Take an OTC lactobacillus preparation (probiotics) and yoghurt with your meals. Drink plenty of fluids (clear soups, water, ORS in water, lemonade). Eat light, do not stay hungry but eat simple things like toast, porridge, cereals, crackers, banana, rice, peeled apple, etc.
Monitor your pain to see if there are any contractions. Inform your Obs and Gyn immediately. Hope this helps. Take care!