How do you diagnose gastro-oesophageal reflux?

Some symptoms already emerge at 2-4 weeks of age. These includes: volcano-like projectile vomits, even out their nostrils; erratic feeding patterns; fussing or in pain after eating; comfortable when upright, but wails when laid down; drooling excessively; having wet hiccups or wet burps; makes choking, gagging noises, may have sour breath or coughing episodes; constant swallowing; constant respiratory problems and poor weight gain. Possible remedies are listed in page 299-300.