Give him a little time to regulate to the new formula. How old is your baby anyway? Long stretches of sleep aren't good for a young baby. Rice cereal in a bottle is a choking hazard and can cause digestive problems and obesity later in life. Its natural for a baby to wake up at least once or multiple times during the night to feed. Just give him another bottles.
5 reasons not to put cereal in a baby's bottle:
#1. You can cause your child's allergies. . .
While no one agrees completely on what it is that actually causes allergies, we do have enough research to see certain connections. One, very well documented connection to serious allergies is when a baby has been exposed to the allergen too early. Putting cereal in your baby's bottle, even rice cereal, can cause allergies.
#2. Choking hazard
Some infants do not fully have their swallowing reflex fully developed at birth. Sucking cereal from a bottle can cause a choking hazard. . .and babies have actually died this way. Choking on cereal from a bottle certainly isn't a common cause of death. . .but why do it when it is linked to something like choking?
#3. Digestive Issues
There is a connection between babies who have solids too early and digestive problems. The fact of the matter is that baby tummies are designed to take in breastmilk. When you can't breastfeed, there's formula which mimics breastmilk. Baby tummies are not designed to take in solids, and it's not surprising that they malfunction when forced to do what they're not designed to do.
#4. Obesity
One key factor in obesity is infant feeding. Infants are born with a self regulatory ability to take in only what they need. By feeding on demand and following a baby's cues, you are essentially helping them form habits of eating when hungry and eating until they feel full. This sets them up for a lifetime of healthy eating habits. But when you add cereal to a bottle, it bypasses their system and essentially they take in more calories than they need.
#5. It Doesn't Work!!!
There is no scientific evidence to support the notion that baby's sleep better with cereal in their bottles. The truth is, babies are designed to wake frequently at night. Dealing with sleep deprivation is part of the parenting package.