A.K.
S.,
My 2 year old suffered from this very phenomenon, also having many watery poops as well. He had no other symptoms, but I was concerned enough to take him to the doc after 2 1/2 weeks. Of course, there was nothing to be done, and the doc simply thought that he had contracted a virus at some point and was still messed up from that. Anyway, the doctor told me to purchase some OTC probiotics that are in pill form. I think the brand is Culterelle. These probiotics are much like what you'll find in yogurt, only they make it all the way to the intestines rather than getting killed in your stomach (according to the doctor). You just open up the capsule and sprinkle half of it onto your child's food (applesauce, oatmeal, whatever). Then repeat procedure with the other half at a separate meal. Since I've started using it, his poops have become much more formed (I was really excited about an actual turd the other day :) and he has not struggled with any constipation.
Good luck!
Amy K