Your infant's digestive system is still a work in progress. One that occasionally requires a little TLC.
Months 4–6 and Beyond
By around 4-6 months, your infant's digestive system and chewing abilities may be ready for some solid foods.
Start introducing solids to your infant's diet with iron-fortified baby rice or barley cereal mixed with breast milk. Make it thin at first, but never mix it into his bottle. You can thicken the cereal as he gets used to the spoon. Next he can move on to mashed or pureed fruits, vegetables and meats. By 6 months, he'll not only want solids, his growing body will need them for their extra nutrition.
The Scoop on Poop
You can tell a lot about your infant's digestion by looking in his diaper. Solid foods mean that infant stools are more solid and come with stronger odors. You may also see bits of undigested fruits or vegetables in there, which is perfectly normal. If his stools are loose and watery, he may have an irritated digestive tract and a call to the doctor is in order.