VOMITING (from romit, from Lat. vomitus, p.p. of romere, to vomit : connected with Gk. E/AEIP, Skt. rem, to vomit). The emptying of the stomach by way of the mouth through its own spasmodic contraction. In a conscious person vomiting is preceded by a feeling of nausea, an increased flow of saliva in the month, and moist ness of the surface due to breaking out of cool perspiration; the face is pale, weakness or abso lute prostration follows. the pulse becomes slower and feeble. The individual may faint. At first the stomach contents are vomited, consisting of food, mucus, and thin serous fluid. if persistent and violent, the vomiting causes the ejection of bile which has regurgitated from the duodenum into the stomach under the pressure of the dia phragm. and rarely of faeces from the intestine. In cirrhosis of the liver blood is vomited, as also in phosphorus poisoning. The 'black vomit' in yellow fever owes its color to blood which es capes into the stomach. In mild attacks of vomit- , ing, such as simply empty an overloaded stomach, the normal state returns immediately. In young infants the act may be simply the revolt of an over-full stomach, and resembles an overflow, without systemic disturbance. In severer attacks of vomiting deep inspiratory efforts are made, dur ing which the diaphragm is thrust down very low against the stomach, while the lower ribs are drawn in. A sudden, violent expiration and con traction of the abdominal wall succeed, adding to the pressure upon the stomach. Besides this, the
longitudinal fibres of the oesophagus are short ened and the cardiac orifice of the stomach is somewhat dilated, and the contents are ejected. The vomiting centre in the medulla may be ex cited by reflex irritation due to peripheral causes, such as tickling the throat, or obstruction of the intestine; or to the presence of renal or biliary calculi. It may be excited by poisons, or by impulses from parts of the cerebrum, due to smells, tastes, and emotions, or by cerebral dis ease. Some emetics act directly on the vomiting centre. for they are efficient if the stomach be cut out and replaced by a bladder filled with water, as in Claude Bernard's celebrated experi ment. Others act reflexly by irritating the mu eons lining of the stomach. Still others develop a nauseating taste, thus affecting a higher centre in the cerebrum.
The treatment of vomiting must he conditioned upon the cause and the accompanying disease. In different conditions mustard applied to the epigastrium. darkness, and the supine posture, or the administration of hot water, aromatic spirit of ammonia, mix vomiea, small doses of ipecacuanha, arsenic, soda, ice, whisky, creosote, chloroform, or entree will relieve. Calomel fre quently is efficacious. Sudden and violent vom iting in healthy person is cause for suspicion of a poisonous agency at work either fermenta tion of improper food o• a drug.