Can eating too much fruit such as papaya, honeydew and watermelon give you watery stools?

These fruits might make one have soft and slightly increase motility because of the fiber, but not watery stool as such. Unless the fruit is not well washed and was contaminated. Slowing down on consumption and monitoring the BM might help identify if any of them is suspect. However, Persisting diarrhea not responding to 24hr BRAT diet suggest one should visit PCP/ Gastroenterologist