4. Waterbrash / W.G. Thompson  

Waterbrash is the spontaneous flooding of the mouth with a clear, slightly salty fluid, which may be of sufficient quantity to require expectoration. 

The source of the fluid appears to be the salivary glands. It is believed to result from a vagal cholinergic reflex, with afferents originating in the upper gastrointestinal tract and efferents destined for the salivary glands. 

The fluid, with a neutral or somewhat salty taste, is quite distinct from the acidic or bitter contents that are refluxed from the stomach. The symptom commonly accompanies upper gastrointestinal distress such as heartburn, peptic ulcer disease and even acute gastroenteritis. By itself, it has no pathologic significance. 

Waterbrash must be distinguished from gastroesophageal reflux disease and rumination. Diagnosis and management depend upon the underlying upper gastrointestinal disorder.