Stool test
A stool test is a medical diagnostic technique that involves the collection and analysis of fecal matter. Microbial analysis (culturing), microscopy and chemical tests are among the tests performed on stool samples. Stool samples should be sent to the laboratory as soon as possible after collection and should not be refrigerated prior to receipt by the laboratory. The patient and/or health care worker in the office or at the bedside is able to make some important observations. Color Texture/consistency—formed Classify type of feces (diagnostic triad for irritable bowel syndrome) based on Bristol stool scale Fecal occult blood test and fecal immunochemical test are the most common stool tests to diagnose many conditions that caused by bleeding in the gastrointestinal system, including colorectal cancer or stomach cancer. The American College of Gastroenterology has recommended the abandoning of gFOBT testing as a colorectal cancer screening tool, in favor of the fecal immunochemical test (FIT). The newer and recommended tests look for globin, DNA, or other blood factors including transferrin, while conventional stool guaiac tests look for heme. Cancers, and to a lesser extent, precancerous lesions, shed abnormal cells into the stool. Cancers and precancerous lesions (polyps) that are ulcerated or rubbed by passing stool also may shed blood into the stool, which can be identified by a hemoglobin assay. The American Cancer Society and the U.S. Preventive Services Task Force recommended colorectal cancer screening with a fecal immunochemical test every year, or a multi-target stool DNA test for every three years from the age of 45. Other options include a sigmoidoscopy or virtual colonoscopy (CT colonography) for every five years or a colonoscopy for every 10 years. Fecal occult blood test is no longer recommended due to the high false-positive rate as well as the dietary and pharmaceutical restrictions. The National Committee for Quality Assurance (NCQA) issued an update to the Healthcare Effectiveness Data and Information Set (HEDIS) for 2017, while the guideline remains for the patients aged 50 or over.
