My son is 6.5 months old. He used to pass stool once in a day or once in 2 days before starting solid food. After starting solid food on completion of 6 months, he initially passed stool once every day and that was solid poop.However, since 2 3 days he is passing stool 3 4 times a day which is loose as it was while he was only breastfeeding. Is it normal!? Why his poop is not solid!? Sometimes poop seems black or green.