Bolus (digestion)

This bolus from an albatross has several ingested flotsam items, including monofilament from fishing nets and a discarded toothbrush, Tern Island, French Frigate Shoals

In digestion, a bolus (from Latin bolus, "ball") is a mass of food that (with animals that can chew) has been chewed at the point of swallowing. Under normal circumstances, the bolus then travels down the esophagus to the stomach for digestion.The National Institute of Diabetes and Digestive and Kidney Diseases Bolus has the same colour as the food that has been chewed by the person and is different from chyme. The bolus is a rolled up ball-like structure formed when the animal is about to swallow. Its pH is alkaline because of the presence of saliva.

Once bolus reaches the stomach, it becomes part of the chyme, which altogether travels through intestines to eventually become feces.

See also

• Chyme
• Chyle