My youngest is 6 months old. He is breastfed, and I started giving him cereal a few weeks after he turned five months. He didn't have any problems with diarrhea. The only thing that seemed different was the texture of his poop. I don't remember my other kids having any problems with rice cereal either. Sorry I couldn't be more helpful!
Mine didn't have it it either. They just went to having less frequent stools. You might ask your pediatrician or maybe stop for a while and see if that is causing the problem? What are you mixing the cereal with?
It is just Pablum Rice cereal and I was just mixing it with breastmilk. Actually, now that I think of it, I don't really think it was diarrhea, it looks the same as it always does, just a whole heck of alot more
I haven't had any diarrhea problems with Jonathan and I've been giving it to him in his bottles in the evenings. He doesn't go as often and the consistency is a little different. I tried the Oatmeal cereal with him, and the consistency changed again.
I know that my step-sister mixed cereal with some fruit or juice once and my nephew made the biggest mess. Before she had even finished feeding him, he had pooped all over his high chair. Phew!