7 month old baby has white poop after eating bananas.... TMI?

My son is 7 months old and we have been giving him mostly prunes and sweet potatoes (Gerber). We started him on bananas this week. He got a little constipated, so we quit the bananas and went back to prunes. I also gave him a 2 ounce bottle of apple juice (again Gerber) to help soften his stool. It worked, but his poop was a really pale pale whitish yellow. It was soft and fluffy....looked like cake frosting. He's back to his normal BM's, but I wanted to know if anyone else has seen this and if I should be worried? I'm taking him to the pediatrician tomorrow, but wanted input from other parents or medical professionals. Thanks!!