What is reflux in babies?

Reflux is the word used to describe what happens when the stomach contents come back up into the gullet or into the mouth. The medical name for gullet is oesophagus (spelt esophagus in the US) So the long name for reflux is gastro-oesophageal reflux disease, shortened to GORD in the UK and GERD in the US.

The diaphragm is the muscle which separates the chest cavity from the abdominal cavity. As the oesophagus passes through the diaphragm, the diaphragm acts like a valve – stopping stomach contents from going backwards up the oesophagus. Doctors refer to this valve mechanism as a sphincter. (see diagram below)

Sometimes the valve action isn’t as strong as it could be. In babies it is because the sphincter action of the diaphragm isn’t fully developed. During the first year of a baby’s life, the sphincter action gradually gets stronger and their chance of having reflux decreases.

Around 50% of babies will get some reflux but in only a small percentage of these is it a real problem. At the age of 10 months the number is down to about one in twenty babies.

Taken from: http://www.babyreflux.co.uk/knowledge/questions/2/What+is+reflux+in...