@inbook{1104503924, author={Michael Laposata and D. Robert Dufour}, editor={Laposata, Michael}, title={The Gastrointestinal Tract}, booktitle={Laboratory Medicine: The Diagnosis of Disease in the Clinical Laboratory}, publisher={McGraw-Hill Education}, address={New York, NY}, year={2014}, url={accessmedicine.mhmedical.com/content.aspx?aid=1104503924} }