A sample of colon tissue is obtained during a colonoscopy procedure using special instruments. The specimen is sent to the laboratory and fixed with special stains. The specimen is examined under the microscope for abnormal findings, such as cancer or inflammation..
Reviewed By: George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, and Stephanie Slon.