Hello girls! We've been having it for 7 days now. The baby has develop…

Hello girls! We've been having it for 7 days now. The baby has developed a small rash on his body in different places and a couple of pimples on his cheeks, watery stools. I breastfeed him, eat all healthy food, nothing sweet or spicy, I don't drink milk, only cottage cheese, yogurt, sour cream a little bit. What could be the cause? From diet or something else, please tell me?