There are numerous reasons why parents can be unhappy with their child's doctor. The best action to take depends on what caused your initial unhappiness. Let's take a look at some common scenarios.
You don't trust your baby's pediatrician
Perhaps your doctor has bad bedside manners, and is rude to you. Perhaps he or she seems absent and approaches seeing patients as a conveyor belt job without taking time to listen to your concerns, or to answer your questions. Perhaps you don't like the rough way in which your doctor examines your child, or perhaps your concerns are even more serious.
A friend of mine recently got charged for dental work that wasn't needed by her pediatric dentist... twice! How did that happen? Well, the dentist didn't allow parents in the exam room, and he did as he pleased. In these cases, the solution is clear: Get a new doctor. Fast.
You disagree on medical issues
Your doctor may prescribe antibiotics more often than you'd like, or could brush your concerns about your baby off as normal without listening. You may even disagree about something much more controversial, like vaccine schedules, when to wean from breastfeeding, or when to introduce solids to babies.
Of course, pediatricians must stay away from giving parenting advice. But you may take a while to see whether your doctor could be right on medical advice, because they did go to medical school. Sometimes, the differences are hard to overcome, and you will want to change doctors.
There are other possible problems too, like your doctor not being available when you need them. I am not suggesting that you change your doctor for every minor problem.
But if there are big issues, you should certainly listen to your gut feelings and make sure that your baby has the best doctor possible. Your baby deserves it!