Abomasum (IMAGE) University of Zurich Caption Sand sinks down in the rumen and collects in the abomasum, passes through the bowel and is then expelled with the undigested material in the feces. Credit (Illustration: UZH) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.