In studying the extensive literature of pylorospasm, one is impressed time and again by the striking uncertainty attending its diagnosis and the difficulty of differentiating this condition from organic stenosis and even from simple vomiting. Most writers on the subject have drawn attention to the diagnostic difficulties and have grouped their cases under the title of pylorospasm in a rather tentative spirit, because, all things considered, the symptoms seemed to point most clearly to a spastic condition. Indeed, diagnosis has not always been possible even after post-mortem examination. The problem, however, is essentially a clinical one, as the majority of cases recover and do not reach autopsy. Few require surgical intervention; so that this opportunity for studying the condition is also not frequently afforded.
As the result of clinical experience some observers have come to the conclusion that there is no pathognomonic sign or symptom which serves to differentiate functional