[236] _Diagnosis_.--The swallowing function can be studied only with the fluoroscope; esophagoscopy for diagnosis, should therefore always be preceded by a fluoroscopic study of deglutition with a barium or other opaque mixture and examination of the thoracic organs to eliminate external pressure on the esophagus as the cause of stenosis. Complete physical examination and Wassermann reaction are further routine preliminaries to any esophagoscopy. Special laboratory tests are done as may be indicated. The physical examination is meant to include a careful examination of the lips, tongue, palate, pharynx, and a mirror examination of the larynx when age permits. _Indications for Esophagoscopy in Disease_.--Any persistent abnormal sensation or disturbance of function of the esophagus calls for esophagoscopy. Vague stomach symptoms may prove to be esophageal in origin, for vomiting is often a complaint when the patient really regurgitates. _Contraindications to Esophagoscopy_.--In the presence of aneurysm, advanced organic disease, extensive esophageal varicosities, acute necrotic or corrosive esophagitis, esophagoscopy should not be done except for urgent reasons, such as the lodgment of a foreign body; and in this case the esophagoscopy may be postponed, if necessary, unless the patient is unable to swallow fluids. Esophagoscopy should be deferred, in cases of acute esophagitis from swallowing of caustics, until sloughing has ceased and healing has strengthened the weak places. The extremes of age are not contraindications to esophagoscopy. A number of newborn infants have been esophagoscoped by the author; and he has removed foreign bodies from patients over 80 years of age. _Water starvation_ makes the patient a very bad surgical subject, and is a distinct contraindication to esophagoscopy. Water must be supplied by means of proctoclysis and hypodermoclysis before any endoscopic or surgical procedure is attempted. If the esophageal stenosis is not readily and quickly remediable, gastrostomy should be done immediately. _Rectal feeding_ will supply water for a limited time, but for nutrient purposes rectal alimentation is dangerously inefficient. _Preliminary examination of the pharynx and larynx with tongue depressor_ should always precede esophagoscopy, for any purpose, because the symptoms may be due to laryngeal or pharyngeal disease that might be overlooked in passing the esophagoscope. A high degree of esophageal stenosis results in retention in the suprajacent esophagus of the fluids which normally are continually flowing downward. The pyriform sinuses in these cases are seen with the laryngeal mirror to be filled with frothy secretion (Jackson's sign of esophageal stenosis) and this secretion may sometimes be seen trickling into the larynx. This overflow into the larynx and lower air passages is often the cause of pulmonary symptoms, which are thus strictly secondary to the esophageal disease. ANOMALIES OF THE ESOPHAGUS