Your baby needs to get their nutrition the best way they can whether it is from the breast or from the bottle. Some days they will eat everything and some days they will leave a little behind. There are some instances in which a parent has to deal with a baby that does not want a bottle after several hours from the last feeding.
Is your baby gaining or losing weight? If your baby's weight is fine, then their body knows that they are getting enough to eat.
Has your baby been eating more during previous feedings? Maybe they had a growth spurt and started drinking four ounces each feeding instead of two. Adding solids may also keep your baby fuller longer. If there is a particular time in which your baby does not want to eat, you may want to consider skipping that feeding time. Your baby's natural instinct lets them know if they are hungry or not. Rather than force the issue, allow their bodies to let them know when they are ready. Keep in mind that your baby needs 2.5 ounces of formula per pound of body weight per day. If your 10-pound baby is consuming 25 ounces each day, then they are getting what their body needs over the course of 24 hours.
Your pediatrician can tell you if there is any reason for concern. Your doctor may look at all of the areas such as weight and temperament to determine that there is nothing wrong with your baby. If you are still concerned after a week or your baby shows adverse reactions to not eating, contact your doctor again.