BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuStool guaiac testColon cancer - guaiac test; Colorectal cancer - guaiac test; gFOBT; Guaiac smear test; Fecal occult blood test - guaiac smear; Stool occult blood test - guaiac smearThe stool guaiac test looks for hidden (occult) blood in a stool sample. It can find blood even if you cannot see it yourself. It is the most common type of fecal occult blood test (FOBT).Guaiac is a substance from a plant that is used to coat the FOBT test cards. How the Test is Performed Usually, you collect a small sample of stool at home. Sometimes, a doctor may collect a small amount of stool from you during a rectal examination.If the test is done at home, you use a test kit. Follow the kit instructions exactly. This ensures accurate results. In brief:You collect a stool sample from 3 different bowel movements. For each bowel movement, you smear a small amount of the stool on a card provided in the kit. You mail the card to a laboratory for testing. DO NOT take stool samples from the toilet bowl water. This can cause errors.For infants and young children wearing diapers, you can line the diaper with plastic wrap. Place the plastic wrap so that it keeps the stool away from any urine. Mixing of urine and stool can spoil the sample. How to Prepare for the Test Some foods can affect test results. Follow instructions about not eating certain foods before the test. These may include:Red meat Cantaloupe Uncooked broccoli Turnip Radish HorseradishSome medicines may interfere with the test. These include vitamin C, aspirin, and NSAIDs such as ibuprofen and naproxen. Ask your health care provider if you need to stop taking these before the test. Never stop or change your medicine without first talking to your provider. How the Test will Feel The at-home test involves a normal bowel movement. There is no discomfort. You may have some discomfort if the stool is collected during a rectal exam. Why the Test is Performed This test detects blood in the digestive tract. It may be done if:You are being screened or tested for colon cancer. Colon cancerColorectal cancer is cancer that starts in the large intestine (colon) or the rectum (end of the colon). Other types of cancer can affect the colon. ...ImageRead Article Now Book Mark Article You have abdominal pain, changes in bowel movements, or weight loss. You have anemia (low blood count). AnemiaAnemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Different type...ImageRead Article Now Book Mark Article You say you have blood in the stool or black, tarry stools. Normal Results A negative test result means that there is no blood in the stool. What Abnormal Results Mean Abnormal results may be due to problems that cause bleeding in the stomach or intestinal tract, including:Colon cancer or other gastrointestinal (GI) tumors TumorsA tumor is an abnormal growth of body tissue. Tumors can be cancerous (malignant) or noncancerous (benign).Read Article Now Book Mark Article Colon polyps Colon polypsA colorectal polyp is a growth on the lining of the colon or rectum.ImageRead Article Now Book Mark Article Bleeding veins in the esophagus or stomach (esophageal varices and portal hypertensive gastropathy) Esophageal varicesThe esophagus (food pipe) is the tube that connects your throat to your stomach. Varices are enlarged veins that may be found in the esophagus in pe...ImageRead Article Now Book Mark Article Inflammation of the esophagus (esophagitis) EsophagitisEsophagitis is a condition in which the lining of the esophagus becomes swollen, inflamed, or irritated. The esophagus is the tube that leads from y...ImageRead Article Now Book Mark Article Inflammation of the stomach (gastritis) from GI infections GastritisGastritis occurs when the lining of the stomach becomes inflamed or swollen. Gastritis can last for only a short time (acute gastritis). It may als...ImageRead Article Now Book Mark Article Hemorrhoids HemorrhoidsHemorrhoids are swollen veins in the anus or lower part of the rectum.ImageRead Article Now Book Mark Article Crohn disease or ulcerative colitis Crohn diseaseCrohn disease is a disease where parts of the digestive tract become inflamed. It most often involves the lower end of the small intestine and the be...ImageRead Article Now Book Mark Article Ulcerative colitisUlcerative colitis is a condition in which the lining of the large intestine (colon) and rectum become inflamed. It is a form of inflammatory bowel ...ImageRead Article Now Book Mark Article Peptic ulcerPeptic ulcerA peptic ulcer is an open sore or raw area in the lining of the stomach or intestine. There are two types of peptic ulcers:Gastric ulcer -- occurs in...ImageRead Article Now Book Mark Article Other causes of positive test may include:Nosebleed Coughing up blood and then swallowing it If the stool guaiac results come back positive for blood in the stool, your doctor will likely order other tests, often including a colonoscopy.ColonoscopyA colonoscopy is an exam that views the inside of the colon (large intestine) and rectum, using a tool called a colonoscope. The colonoscope has a sm...ImageRead Article Now Book Mark Article The stool guaiac test does not diagnose cancer. Screening tests such as colonoscopy can help detect cancer. The stool guaiac test and other screenings can catch colon cancer early, when it is easier to treat. Risks There can be false-positive and false-negative results. Errors are reduced when you follow instructions during collection and avoid certain foods and medicines. Open ReferencesReferencesRex DK, Boland CR, Dominitz JA, et al. Colorectal cancer screening: recommendations for physicians and patients from the U.S. Multi-Society Task Force on colorectal cancer. Am J Gastroenterol. 2017;112(7):1016-1030. PMID: 28555630 pubmed.ncbi.nlm.nih.gov/28555630/.Savides TJ, Jensen DM. Gastrointestinal bleeding. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 20.US Preventive Services Task Force, Bibbins-Domingo K, Grossman DC, et al. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA. 2016;315(23):2564-2575. PMID: 27304597 pubmed.ncbi.nlm.nih.gov/27304597/.AllVideoImagesTogFecal occult blood test - illustration A fecal occult blood test is a noninvasive test that detects the presence of hidden blood in the stool. Blood in the stool that is not visible is often the first, and in many cases the only, warning sign that a person has colorectal disease, including colon cancer. Fecal occult blood testillustrationFecal occult blood test - illustration A fecal occult blood test is a noninvasive test that detects the presence of hidden blood in the stool. Blood in the stool that is not visible is often the first, and in many cases the only, warning sign that a person has colorectal disease, including colon cancer. Fecal occult blood testillustration Tests for Stool guaiac test Stool guaiac testRelated Information Colorectal polyps(Condition)Colorectal cancer(Condition)Tumor(Condition)Esophagitis(Condition)Gastritis(Condition)Hemorrhoids(Condition)Crohn disease(Condition)Peptic ulcer(Condition)Bleeding esophageal varices(Condition)Colon and rectal cancers(In-Depth)Crohn disease(In-Depth)Peptic ulcers(In-Depth) Review Date: 1/15/2020 Reviewed By: Michael M. Phillips, MD, Clinical Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Internal review and update on 06/03/2021 by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.
Stool guaiac testColon cancer - guaiac test; Colorectal cancer - guaiac test; gFOBT; Guaiac smear test; Fecal occult blood test - guaiac smear; Stool occult blood test - guaiac smearThe stool guaiac test looks for hidden (occult) blood in a stool sample. It can find blood even if you cannot see it yourself. It is the most common type of fecal occult blood test (FOBT).Guaiac is a substance from a plant that is used to coat the FOBT test cards. How the Test is Performed Usually, you collect a small sample of stool at home. Sometimes, a doctor may collect a small amount of stool from you during a rectal examination.If the test is done at home, you use a test kit. Follow the kit instructions exactly. This ensures accurate results. In brief:You collect a stool sample from 3 different bowel movements. For each bowel movement, you smear a small amount of the stool on a card provided in the kit. You mail the card to a laboratory for testing. DO NOT take stool samples from the toilet bowl water. This can cause errors.For infants and young children wearing diapers, you can line the diaper with plastic wrap. Place the plastic wrap so that it keeps the stool away from any urine. Mixing of urine and stool can spoil the sample. How to Prepare for the Test Some foods can affect test results. Follow instructions about not eating certain foods before the test. These may include:Red meat Cantaloupe Uncooked broccoli Turnip Radish HorseradishSome medicines may interfere with the test. These include vitamin C, aspirin, and NSAIDs such as ibuprofen and naproxen. Ask your health care provider if you need to stop taking these before the test. Never stop or change your medicine without first talking to your provider. How the Test will Feel The at-home test involves a normal bowel movement. There is no discomfort. You may have some discomfort if the stool is collected during a rectal exam. Why the Test is Performed This test detects blood in the digestive tract. It may be done if:You are being screened or tested for colon cancer. Colon cancerColorectal cancer is cancer that starts in the large intestine (colon) or the rectum (end of the colon). Other types of cancer can affect the colon. ...ImageRead Article Now Book Mark Article You have abdominal pain, changes in bowel movements, or weight loss. You have anemia (low blood count). AnemiaAnemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Different type...ImageRead Article Now Book Mark Article You say you have blood in the stool or black, tarry stools. Normal Results A negative test result means that there is no blood in the stool. What Abnormal Results Mean Abnormal results may be due to problems that cause bleeding in the stomach or intestinal tract, including:Colon cancer or other gastrointestinal (GI) tumors TumorsA tumor is an abnormal growth of body tissue. Tumors can be cancerous (malignant) or noncancerous (benign).Read Article Now Book Mark Article Colon polyps Colon polypsA colorectal polyp is a growth on the lining of the colon or rectum.ImageRead Article Now Book Mark Article Bleeding veins in the esophagus or stomach (esophageal varices and portal hypertensive gastropathy) Esophageal varicesThe esophagus (food pipe) is the tube that connects your throat to your stomach. Varices are enlarged veins that may be found in the esophagus in pe...ImageRead Article Now Book Mark Article Inflammation of the esophagus (esophagitis) EsophagitisEsophagitis is a condition in which the lining of the esophagus becomes swollen, inflamed, or irritated. The esophagus is the tube that leads from y...ImageRead Article Now Book Mark Article Inflammation of the stomach (gastritis) from GI infections GastritisGastritis occurs when the lining of the stomach becomes inflamed or swollen. Gastritis can last for only a short time (acute gastritis). It may als...ImageRead Article Now Book Mark Article Hemorrhoids HemorrhoidsHemorrhoids are swollen veins in the anus or lower part of the rectum.ImageRead Article Now Book Mark Article Crohn disease or ulcerative colitis Crohn diseaseCrohn disease is a disease where parts of the digestive tract become inflamed. It most often involves the lower end of the small intestine and the be...ImageRead Article Now Book Mark Article Ulcerative colitisUlcerative colitis is a condition in which the lining of the large intestine (colon) and rectum become inflamed. It is a form of inflammatory bowel ...ImageRead Article Now Book Mark Article Peptic ulcerPeptic ulcerA peptic ulcer is an open sore or raw area in the lining of the stomach or intestine. There are two types of peptic ulcers:Gastric ulcer -- occurs in...ImageRead Article Now Book Mark Article Other causes of positive test may include:Nosebleed Coughing up blood and then swallowing it If the stool guaiac results come back positive for blood in the stool, your doctor will likely order other tests, often including a colonoscopy.ColonoscopyA colonoscopy is an exam that views the inside of the colon (large intestine) and rectum, using a tool called a colonoscope. The colonoscope has a sm...ImageRead Article Now Book Mark Article The stool guaiac test does not diagnose cancer. Screening tests such as colonoscopy can help detect cancer. The stool guaiac test and other screenings can catch colon cancer early, when it is easier to treat. Risks There can be false-positive and false-negative results. Errors are reduced when you follow instructions during collection and avoid certain foods and medicines. Open ReferencesReferencesRex DK, Boland CR, Dominitz JA, et al. Colorectal cancer screening: recommendations for physicians and patients from the U.S. Multi-Society Task Force on colorectal cancer. Am J Gastroenterol. 2017;112(7):1016-1030. PMID: 28555630 pubmed.ncbi.nlm.nih.gov/28555630/.Savides TJ, Jensen DM. Gastrointestinal bleeding. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 20.US Preventive Services Task Force, Bibbins-Domingo K, Grossman DC, et al. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA. 2016;315(23):2564-2575. PMID: 27304597 pubmed.ncbi.nlm.nih.gov/27304597/.
