Regurgitation (digestion)
Expulsion of material from pharynx or esophagus, often for feeding young.
Regurgitation is the expulsion of material from the pharynx or esophagus, usually characterized by the presence of undigested food or blood. It is a normal and voluntary process in most animals, unlike the complex vomiting reflex in response to toxins. Regurgitation is used by a number of species to feed their young, particularly when the young are at a fixed location and a parent must forage or hunt, especially under circumstances where carriage of small prey would be subject to robbing or the whole prey is larger than can be carried to a den or nest.
- definition
- Expulsion of material from pharynx or esophagus
- common in infants
- 67% of 4-month-old infants spit up more than once per day
- human disorder
- Rumination syndrome, a rare and often misdiagnosed disorder
- bird feeding strategy
- Used by seabirds and Suliformes to feed young
- other animal use
- Ruminants regurgitate food as normal part of digestion; honey bees produce honey by regurgitation
- defense mechanism
- Some birds, such as fulmars, employ regurgitation as a defense when threatened
Lore & Background
Regurgitation is a voluntary process in most animals, used for feeding young, digestion, or defense. In humans, it can be voluntary or involuntary, occurring with gastroesophageal reflux disease (GERD), acid reflux, or anatomical abnormalities. Chronic involuntary regurgitation, known as rumination syndrome, is rare and often misdiagnosed. Some people, including practitioners of yoga and professional regurgitators, can regurgitate through muscle control without external stimulation.
Reader's Guide
Regurgitation serves critical biological functions across species. In birds, especially seabirds and Suliformes, it allows parents to transport food over long distances without risk of theft by other birds. The practice supports brood hierarchies in species like the blue-footed booby, where older chicks may dominate feeding, and in times of scarcity, siblicide can occur. In ruminants, regurgitation aids digestion by allowing cud chewing to reduce particle size. Honey bees produce honey through regurgitation, storing it as a primary food source. In humans, regurgitation is common in infants and can be a symptom of GERD or rumination syndrome. The process is distinct from vomiting, being voluntary and not a response to toxins.
Did You Know?
- 67% of 4-month-old infants spit up more than once per day.
- Some birds, such as fulmars, employ regurgitation as a defense when threatened.
- Ruminants regurgitate their food as a normal part of digestion, chewing the cud to increase digestibility.
- Honey is produced by a process of regurgitation by honey bees.
Frequently Asked Questions
What is regurgitation in the context of digestion?
Regurgitation is the voluntary or passive expulsion of undigested material from the pharynx or esophagus back out of the mouth. It is a simple mechanical act rather than the complex, toxin-triggered neuromuscular reflex that defines vomiting.
How does regurgitation differ from vomiting?
Regurgitation is a relatively straightforward, voluntary push of food back up from the esophagus, while vomiting is a powerful involuntary reflex that coordinates the diaphragm, abdominal wall, and stomach to forcefully eject contents. Regurgitated material is typically still undigested, whereas vomit often contains bile or gastric acid.
Why do seabirds and Suliformes regurgitate food for their chicks?
These birds forage far from the nest and must deliver prey back to stationary, nest-bound young. Regurgitation is especially advantageous when the catch is too large to carry or when small prey would be stolen by competitors during the trip to the nest.
What is rumination syndrome in humans?
Rumination syndrome is a rare condition in which a person repeatedly regurgitates recently ingested food, often re-chews or discards it, and is frequently misdiagnosed as a structural or motility disorder of the gut. It is distinct from the brief, normal spit-up episodes experienced by roughly two-thirds of four-month-old infants.
How do ruminants and honey bees employ regurgitation?
Ruminants such as cattle and sheep regurgitate partially fermented cud back into the mouth for re-chewing as a routine step in their multi-chambered digestive cycle. Honey bees, on the other hand, regurgitate nectar into comb cells where it is fanned and concentrated into honey.
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