In general, acute abdominal diseases are of four pathological types: obstructive, infectious, hemorrhagic, and vascular. Frequently a combination of these types is observed, as in obstructions incident to infection and inflammatory edema, and in hemorrhagic pancreatitis. Together, they may produce that most serious emergency: peritonitis. The outstanding symptom of all acute abdominal disease is pain. The onset of the pain, whether gradual or sudden; its origin and distribution; its severity; and its type and duration, whether constant or remittent, are often of diagnostic significance, as are the time of onset of symptoms of nausea and vomiting; the type of the vomiting, whether profuse, projectile, or otherwise; and the contents of the material. Additional valuable information may be gained from a history of intestinal disturbances and from any abnormality of the color and contents of the stools. A careful investigation of the foregoing symptoms, correlated with the findings on physical examination,