Reflux (or acid reflux) is sadly quite common among children with autism.

Often, because these children cannot communicate well, the problem goes undiagnosed, resulting in more and more damage and on-going pain. Signs of reflux include heartburn (clutching, rubbing, or hitting at the chest, especially following meals), regurgitation (unexplained chewing or swallowing), bitter taste in the mouth (rubbing or pulling at the inside of the mouth), hoarseness, wheezing, dry cough, respiratory problems, vomiting, refusal of food, and crying as if in pain.

A good introduction to reflux can be found here

Often practitioners will want to test for reflux and provide prescriptions in an effort to break the cycle and interrupt the damage being caused.

Poor enzyme production is common among children with autism, and many children show improvements after enzymes are introduced. Do note that initially introducing enzymes can cause some negative behaviours. For more on enzymes see www.enzymestuff.com