While diarrhea and lower abdominal pain can sometimes be early signs of labor, they are not definitive indicators on their own. It's important to consider other factors such as the frequency and intensity of contractions, the presence of bloody show or water breaking, and any other symptoms you may be experiencing. If you're unsure or concerned, it's best to contact your healthcare provider for guidance. They will be able to assess your specific situation and provide appropriate advice based on your individual circumstances.