DESCRIPTION

• Vomiting is the forceful expulsion of gastric contents through the mouth.
  • A prominent feature of many disorders of infancy and childhood
  • Often the only presenting symptom
• Regurgitation is defined as small, effortless mouthfuls of food or stomach contents.
• Retching is contraction of the abdominal musculature against a closed glottis, restricting expulsion of stomach contents (also referred to as “dry heaves”).

PATHOPHYSIOLOGY

Vomiting may be indicative of a number of different physiologic pathways, including as:

• A defense mechanism to expel ingested toxins
• An abnormality of, or damage to, the postrema area of the brain (a.k.a. the chemoreceptor trigger zone or vomiting center), which is located at the base of the 4th ventricle
• A result of intestinal obstruction leading to bowel dilation
• A reaction to chronic gastrointestinal mucosal disease
• A result of a generalized metabolic disease
• A sequela of increased intracranial pressure