Children and Diarrhea
If your child has diarrhea and is not vomiting or has only vomited a few times, then you can continue his usual diet (including breastfeeding or formula), but do give 2-4 ounces of extra fluid every time that he has a large watery diarrhea. Although your child will not be able to digest everything that he eats as well as he normally would, by eating a regular diet your child will continue to get the nutrition he needs to get well.
If your child does not want to eat the first day then you can try the typical BRAT diet (bananas, rice, applesauce and toast) with lots of fluids, and then advance his diet as quickly as he will tolerate it.
If your child has had prolonged diarrhea, then he may rarely develop a temporary lactase deficiency and may not be able to tolerate dairy products. You can try a soy formula or soy milk for a few weeks if your child's diarrhea becomes worse after drinking dairy products.