What is the best course of action for an elderly patient with narrowed stools for 5 weeks, last colonoscopy over 10 years ago, and a normal Fecal Immunochemical Test (FIT) 3 years ago?

Urgent Colonoscopy Required

This elderly patient with new-onset narrowed stools for 5 weeks requires urgent colonoscopy regardless of prior screening history or negative FIT 3 years ago, as this represents an alarm symptom that mandates immediate evaluation for colorectal cancer. 1

Why This Patient Cannot Wait

• Narrowed stools are a red flag symptom that suggests possible obstructing colorectal lesion and requires direct visualization with colonoscopy, not repeat stool testing 1
• The 10-year interval since last colonoscopy has expired, making this patient overdue for screening even without symptoms 2
• A normal FIT from 3 years ago is irrelevant because FIT has poor sensitivity for advanced adenomas (which don't commonly bleed) and this patient is now symptomatic 3
• FIT is not recommended for symptomatic patients due to increased risk of advanced-stage disease and should never delay diagnostic colonoscopy 4

Age-Appropriate Screening Considerations

While screening decisions in patients aged 76-85 typically require individualization based on life expectancy and comorbidities 2, this patient has alarm symptoms that override age-based screening guidelines. The presence of new bowel habit changes (narrowed stools) converts this from a screening scenario to a diagnostic evaluation 2, 1.

Colonoscopy Quality Requirements

• The examination must be complete to the cecum with photo-documentation of the appendiceal orifice, ileocecal valve, or terminal ileum 2
• Adequate bowel preparation is critical to ensure visualization of mucosal changes 2
• Biopsies should be obtained from any suspicious lesions and from normal-appearing mucosa if chronic diarrhea is also present 1

Timeline for Completion

• Schedule colonoscopy within 30 days of presentation with alarming symptoms, with maximum acceptable delay of 6 months but aiming for completion within 3 months 4
• Do not delay for repeat FIT or other non-invasive testing, as colonoscopy is mandatory when alarm features are present 1, 4

Common Pitfalls to Avoid

• Do not reassure based on negative FIT 3 years ago - FIT has limited sensitivity for non-bleeding lesions and loses all relevance when alarm symptoms develop 3
• Do not defer colonoscopy based on age alone - symptomatic patients require diagnostic evaluation regardless of screening guidelines 2, 1
• Do not order CT colonography as an alternative - direct optical colonoscopy with biopsy capability is required for diagnostic evaluation of alarm symptoms 1
• Do not assume functional cause - new-onset symptoms in elderly patients have high pretest probability for organic pathology including malignancy 1

If Colonoscopy is Negative

Should colonoscopy fail to identify a cause for narrowed stools, consider:

• Upper endoscopy to evaluate for gastric or small bowel pathology 4
• Small bowel imaging with capsule endoscopy if symptoms persist 4
• Pelvic floor dysfunction evaluation if structural lesions are excluded 1