@inbook{1198711238,
author={William L. Hasler and Chung Owyang},
editor={Loscalzo, Joseph and Fauci, Anthony and Kasper, Dennis and Hauser, Stephen and Longo, Dan and Jameson, J. Larry},
title={Approach to the Patient with Gastrointestinal Disease},
booktitle={Harrison's Principles of Internal Medicine, 21e},
publisher={McGraw-Hill Education},
address={New York, NY},
year={2022},
url={accessmedicine.mhmedical.com/content.aspx?aid=1198711238}
}