My 4 month old has no signs of illness other than green diarrhea that has a fishy odor to it. His diarrhea diaper have decreased from 8 to 4 in the past day. It s been a total of five days of experiencing this. He is up to date in his immunizations and the dr seemed quite impressed with his growth, health and well-being at his last visit. There is no vomiting and no fever. His little heiney is getting sore. What is this? Help! He is a strictly breadtfed baby.