reticulo-omasal orifice

Aperture in the gastric groove as it passes from the reticulum into the omasum. Obstruction by a foreign body causes ruminal distention and hypermotility and the passage of small amounts of feces. See also vagus indigestion.

• r.-o. sphincter achalasia — part of the vagus indigestion pathogenesis; causes accumulation of ingesta in the reticulorumen. Called also anterior functional stenosis.