Nope, has never had banana. Tried apple for a couple of days and that stopped her right up. Also has never had rice cereal because I knew she was prone to constipation. Her diet for the past couple of days has included barley cereal, sweet potato, peas, green beans, winter squash, avocado, cantaloupe and pears. Anything in there that could be the culprit? I've been adding extra water and a small amount of prune juice to her bottles, and even gave her some gerber prunes with her cereal this morning. Nothing seems to have helped yet.