Related Experiment Video
Updated: May 5, 2026

Evaluation of Colorectal Cancer Risk and Prevalence by Stool DNA Integrity Detection
Published on: June 8, 2020
Accuracy of screening for fecal occult blood on a single stool sample obtained by digital rectal examination: a
Judith F Collins1, David A Lieberman, Theodore E Durbin
1Department of Veterans Affairs Medical Centers, Portland, Oregon 97239, USA.
Background:
Many expert panels recommend colorectal cancer screening for average-risk asymptomatic individuals older than 50 years of age. Recent studies have found that 24% to 64% of primary care providers use only the digital fecal occult blood test (FOBT) as their primary screening test. The effectiveness of a single digital FOBT is unknown.
Objective:
To compare the sensitivity and specificity of digital FOBT and the recommended 6-sample at-home FOBT for advanced neoplasia in asymptomatic persons.
Design:
Prospective cohort study.
Setting:
13 Veterans Affairs medical centers.
Patients:
3121 asymptomatic patients 50 to 75 years of age.
Intervention:
2665 patients had 6-sample at-home FOBT and digital FOBT, followed by complete colonoscopy.
Measurements:
We measured the sensitivity of digital and 6-sample FOBT for advanced neoplasia and the specificity for no neoplasia. We calculated predictive values and likelihood ratios for advanced neoplasia, defined as tubular adenomas 10 mm or greater, adenomas with villous histology or high-grade dysplasia, or invasive cancer.
Results:
Of all participants, 96.8% were men; their average age was 63.1 years. The 6-sample FOBT and the single digital FOBT had specificities of 93.9% and 97.5%, respectively, as defined by studying 1656 patients with no neoplasia. Sensitivities for detection of advanced neoplasia in 284 patients were 23.9% for the 6-sample FOBT and 4.9% for the digital FOBT. The likelihood ratio for advanced neoplasia was 1.68 (95% CI, 0.96 to 2.94) for positive results on digital FOBT and 0.98 (CI, 0.95 to 1.01) for negative results.
Limitations:
Most patients were men.
Conclusions:
Single digital FOBT is a poor screening method for colorectal neoplasia and cannot be recommended as the only test. When digital FOBT is performed as part of a primary care physical examination, negative results do not decrease the odds of advanced neoplasia. Persons with these results should be offered at-home 6-sample FOBT or another type of screening test.
More Related Videos
04:57Comparative Analysis of Automatic Fecal Analyzer versus Direct Wet Smear Microscopy for Detecting Parasitic Infections in Stool Samples
Published on: April 25, 2025
04:56Detection of Helicobacter pylori Infection and Antibiotic Resistance via Stool Quantitative Polymerase Chain Reaction Analysis
Published on: May 16, 2025
Related Concept Videos
Assessing Body Temperature - Rectal
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
Assessment of the Rectum and Anus
Rectal Inspection
Begin by inspecting the perianal and anal areas for color, texture, rashes,...
Serum Laboratory Studies, Stool Test, Breath Test
Imaging Studies III: Gastrointestinal Motility Studies and Virtual Colonoscopy
Radionuclide Testing
Radionuclide testing is a sophisticated medical technique for assessing gastrointestinal motility. It focuses on gastric emptying and colonic transit time. Radioactive markers track the movement of food through the digestive system, providing insights into gastrointestinal disorders.
In gastric emptying studies, a meal's liquid and...