What to do after a positive Hemosure (Fecal Occult Blood Test) result?

Management of Positive Hemosure (Fecal Occult Blood Test) Result

A positive Hemosure (Fecal Occult Blood Test) result should be followed by a colonoscopy to examine the entire colon, not by repeating the FOBT or performing limited examinations. 1

Appropriate Next Steps

• Colonoscopy is the definitive follow-up test after a positive FOBT, allowing for direct visualization of the entire colon and providing the opportunity to identify and remove adenomatous polyps or detect colorectal cancer at an early stage 1
• Colonoscopy should be performed within 60 days of a positive FOBT result to minimize the risk of disease progression 1
• The British Society of Gastroenterology guidelines emphasize that faecal occult blood testing is insensitive and non-specific as a diagnostic tool, making follow-up colonoscopy essential 2

Common Pitfalls to Avoid

• Repeating the FOBT after a positive result is inappropriate and delays proper diagnostic evaluation 1
• Following up with flexible sigmoidoscopy alone is inadequate as it only visualizes the distal portion of the colon and may miss significant lesions 1, 2
• Attributing a positive Hemosure test to hemorrhoids without further investigation is a dangerous practice, as hemorrhoids and colorectal cancer can coexist 3
• Single-sample in-office FOBT collected during digital rectal examination has extremely poor sensitivity (only 4.9% for advanced neoplasia) and should not be used for screening 1, 4

Clinical Significance of Positive FOBT

• Studies show that 61.61% of patients with positive FOBT who undergo colonoscopy have polyps or adenocarcinoma 5
• Adenocarcinoma is found in approximately 9.71% of patients with positive FOBT who undergo colonoscopy 5
• Higher quantitative test results are associated with increased likelihood of finding adenomatous polyps and colorectal cancer 5
• Without proper follow-up, a positive FOBT may provide a false sense of security, as up to 62% of advanced colorectal cancers can be missed by FOBT alone 6

Considerations During Colonoscopy

• Complete colonic evaluation is mandatory when a positive Hemoccult test is present, even if the patient has hemorrhoids or other apparent causes of bleeding 3
• During colonoscopy, any polyps found should be removed and biopsies taken of suspicious lesions 1
• If colonoscopy cannot be completed, a double contrast barium enema is a sufficient alternative 2

Special Populations

• In patients with severe co-morbidity or advanced age, the appropriateness of invasive investigation should be carefully considered and discussed with patients and carers 2
• For pre-menopausal women with positive FOBT, gynecological causes of bleeding should also be considered, but this does not eliminate the need for colonoscopy 2

Follow-up After Colonoscopy

• If colonoscopy is negative, iron supplementation should be considered if the patient has iron deficiency anemia 2
• After treatment of any identified lesions, monitoring of hemoglobin levels and red cell indices is recommended at three-month intervals for one year and then after a further year 2
• Further investigation is only necessary if hemoglobin or MCV falls below normal during follow-up 2

Remember that a positive FOBT result should never be ignored or attributed to benign causes without proper investigation, as this could lead to delayed diagnosis of colorectal cancer and poorer outcomes.