What is Projectile Vomiting?
Projectile vomiting is vomit that exits the mouth with such force in that it is propelled over a short but significant distance. It is often sudden with excessive vomitus passed out in each attack.
Nausea usually does not precede projectile vomiting and it can occur suddenly without any indication of discomfort or gastrointestinal upset. However, the term ‘projectile vomiting‘ is often used quite indiscriminately to refer to any type of severe vomiting. For it to be termed as projectile, the pressure has to be significantly high within the gut and the vomitus has to be propelled a distance away from the body ( sometime even several feet). Overall, projectile vomiting is quite violent.
As explained under the process of vomiting, the contractions that propel the upper gut contents out as vomitus starts from as low as the middle of the small intestine. Depending on the rate and intensity of the contraction, vomiting can be fairly forceful.
Causes of Projectile Vomiting
Projectile vomiting is often associated with gastric outlet obstruction. This is where the passage of the stomach contents into the small intestine is either partially or completely obstructed. However, any very strong stimulus that triggers the chemoreceptor trigger zone (CTZ) or vomit centers in the medulla could possibly result in projectile vomiting.
The following causes need to be taken into account in babies, children and adults :
- Gastric or bowel obstruction
- Other causes of delayed gastric emptying
- Raised intracranial pressure, especially if it is of sudden onset
- Overeating (force feeding)
Gastric outlet obstruction is discussed below in terms of more likely causes in infants or children and adults.
Raised intracranial pressure may occur due to a number of reasons. Hydrocephalus, intracranial bleeding (hemorrhage), tumor or infections like meningitis or encephalitis need to be considered as possible causes. Raised intracranial pressure should always be investigated in vomiting following head injury.
Overeating, whether voluntary or forced, if sudden can cause significant distension of the esophagus, stomach and/or duodenum and impair gut motility.
Projectile Vomiting in Infants and Children
In infants and children, stomach or bowel obstruction is one of the more common causes of projectile vomiting. With newborn babies and infants, gastric outlet obstruction is often due to pyloric stenosis. This is often congenital and is usually seen within the first 3 months of birth. It typically presents with forceful vomit that does not contain bile. However, if the obstruction lies distal to the pylorus, as in duodenal atresia, the vomitus may contain bile (bile vomit).
Intussusception, Hirschsprung’s disease and malrotation need to be considered as well.
In toddlers and older children, an ingested foreign object may cause an obstruction within the upper gut. Abdominal pain of sudden onset which aggravates upon eating or attempting to defecate and is tender to touch should raise the question about a foreign object. This is more common among toddlers than other age groups. Ingestion of caustic substances may also be a cause.
Projective Vomiting in Adults
Gastric outlet obstruction is also a common cause of projectile vomiting in adults but often for different reasons from that of infants. Peptic ulcer disease, gallstone obstruction (Bouveret syndrome) or gastric or duodenal polyps are more likely causes.
The intake of certain toxins in poisoning, either intentional or accidental, may cause excessive irritation of the gut lining, thereby triggering a strong response from the vomiting centers and resulting in projectile vomiting. In small doses, however, these poisons may enter the system unnoticed.
The use of emetics, either in patients with eating disorders or sometimes used culturally for purging, may also trigger projectile vomiting. These practices are usually discouraged as the chances of complication like a Mallory-Weiss tear or eosophageal rupture is significantly high if excessive amounts or frequent use of an emetic is the norm.
Rare or Unusual Causes and Considerations
Rare or unusual causes may include psychogenic causes. Extreme fear or shock may produce sufficiently strong stimuli to trigger forceful or violent vomiting. In children, abuse has to always be a consideration. Highly disturbing and unpleasant images or sounds could also lead to violent vomiting. While rare, for projectile vomiting to occur due to psychogenic causes, the stimulus or intensity of emotion has to be extreme and the person has to have eaten within a short period prior to the event.
Shaken baby syndrome may cause sudden increase in intracranial pressure or spinal cord injury, both of which may contribute to projectile vomiting.
Kidney problems may lead to a number of changes in blood pH and composition (acidosis, uremia). Some of these substances, when in high concentrations, could prove to be strong stimulating factors for the chemoreceptor trigger zone.