title: The configuration of the human gastroduodenal junction in the separate emptying of liquids and solids.
abstract: BACKGROUND
  The stomach separately empties liquids and large particulate solids. The present study aimed to better define the mechanisms responsible for this separate emptying in humans.
  
  
  METHODS
  Real-time ultrasound images of the gastroduodenal junction were tape-recorded in normal volunteers after they ingested a test meal consisting of beans and chicken broth.
  
  
  RESULTS
  During early emptying, beans were retained along the gastric greater curve as it bulged caudally. When the pylorus was open, liquids flowed over the beans into the duodenum. Emptying of the occasional bean that appeared in the antrum was blocked by closure of the pylorus. Later, the antrum was tubular in shape with reduced area of cross section, yet the percent narrowing of the lumen with each contraction remained constant. Beans were now in close contact with the contracting antral wall and were transformed into small particles. Only in this state were solids allowed through the pylorus.
  
  
  CONCLUSIONS
  Mechanisms by which the human stomach "sieves" liquids from solids include (1) sedimentation of solids in the dependent portion of the stomach, while liquids are "decanted" into the duodenum in early emptying; (2) blockade of large particles from entering the duodenum by closure of the pylorus; and (3) grinding of large particles by the gastric antrum in late emptying.
authors.affiliation: Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City.
authors.forename: B P
authors.initials: BP
authors.lastname: Brown
authors.forename: K
authors.initials: K
authors.lastname: Schulze-Delrieu
authors.forename: J E
authors.initials: JE
authors.lastname: Schrier
authors.forename: M M
authors.initials: MM
authors.lastname: Abu-Yousef
mesh_terms: D000328:Adult; D003199:Computer Systems; D004386:Duodenum / Q000000981:diagnostic imaging*; D004435:Eating; D005260:Female; D005746:Gastric Emptying; D005766:Gastrointestinal Contents; D006801:Humans; D008297:Male; D013270:Stomach / Q000000981:diagnostic imaging*; D013997:Time Factors; D014463:Ultrasonography