If your child experiences the following symptoms, you should talk to your child's doctor.
Chest pain
When stomach acid is refluxed into the esophagus, pain can occur behind the breastbone and higher into the chest and throat. Chest pain is a symptom that should always be evaluated by a doctor.
Burning sensation in the throat
If refluxed stomach acid irritates the esophagus, it can cause a burning sensation in the throat and lower esophagus.
Gagging or choking
Trouble with swallowing (dysphagia) occurs when food does not pass normally from the mouth through the esophagus to the stomach. There may be a sensation of food sticking in the throat, chest pressure or "burning" after eating, or a feeling of choking. Difficulty swallowing could be a sign of various conditions, including erosive esophagitis, and should always be evaluated by a physician.
Frequent sore throat
When stomach contents back up into the throat, it can cause irritation and a sore throat.
Respiratory problems (such as bronchitis, wheezing, asthma)
Several studies suggest a significant link between GERD and asthma. GERD can affect asthma when refluxed acid from the stomach is aspirated into the lungs, and can make breathing difficult and cause the child to wheeze and cough.
Hoarseness
Irritation caused by refluxed stomach acid into the throat can lead to hoarseness.
Poor sleep, frequent waking
When a child is sleeping and his head isn't elevated, stomach contents can press against the lower esophageal sphincter, causing it to open inappropriately. This can lead to coughing and a choking sensation, which in turn can make sleeping more difficult.
Sources:
Marsha Kay, M.D., Vasundhara Tolia, M.D.. "COMMON GASTROINTESTINAL PROBLEMS IN PEDIATRIC PATIENTS."; The American College of Gastroenterology. 10 Dec 2009.
"Heartburn, Hiatal Hernia, and Gastroesophageal Reflux Disease (GERD)." NIH Publication No. 07–0882 May 2007. National Digestive Diseases Information Clearinghouse. Accessed on 10 Dec 2009.
Brian Pace, MA, Richard M. Glass, MD. "Gastroesophageal Reflux in Children." JAMA, July 19, 2000---Vol 284, No. 3. The Journal of the American Medical Association. 10 Dec 2009.

