Since you don't have a doctor's diagnosis yet, you should probably try some natural remedies to help with the burning. Papaya and Pineapple both have enzymes that assist in digestion and Papaya actually contains papain which has a soothing quality. You can read what Dr Eisner has to say about Papaya and Pineapple here in this share post.
There are also some tips for making children and babies more comfortable here. Tracy Davenport is the mom of a child with Reflux. You can read about Tracy here, but she also has a very good article about making the most of your doctor's appointments here.
Online sources are great to help you ask all the questions you need to ask, but they can not take the place of your doctor's advice. It is best to have your child see the doctor and then go on from there.
Take care and let us know how the child is doing!Vicki M
I am sure it is tempting to try an over the counter medication for heartburn/GERD. There are so many brands on the pharmacy shelf. It is really important to take your six year old to the doctor for a diagnosis and treatment plan. It may turn out that a change to the diet or eating habits will control the heartburn. If a medication is needed, your doctor can recommend the best type of medication and dosage. The medication may be over the counter or prescription.