How should a visual and digital examination of an anal fissure be performed when the perianal region is painful?

Examination of Anal Fissures in the Setting of Severe Pain

When the perianal region is too painful for adequate examination, sedation or anesthesia should be used to perform a complete anorectal examination, including digital rectal examination and direct visualization. 1

Initial Visual Inspection Without Instrumentation

• Begin with gentle buttock traction to efface the anal canal and visualize the fissure without inserting any instruments into the anal canal. 2
• This technique allows direct visualization of the fissure location, which is typically posterior midline in 90% of cases. 2
• Do not use end-viewing endoscopes for fissure visualization, as they cannot adequately visualize the anal verge and anoderm where fissures occur. 2

Pain Management During Examination

• Topical anesthetics (lidocaine 5%) should be applied to the anal verge to provide local pain relief during the initial inspection. 1, 3
• If pain remains severe despite topical anesthesia, do not force instrumentation or digital examination in the awake patient, as this is inappropriate and traumatic. 2

When to Proceed to Examination Under Anesthesia

Examination under anesthesia is warranted when:

• Significant anal pain prevents comfortable diagnosis in the office setting 2
• Digital rectal examination cannot be performed due to intense pain 1
• Complete assessment of the anorectal region is needed to rule out abscess, fistula, or other pathology 1

The 2021 WSES-AAST guidelines explicitly state that while complete anorectal examination including digital rectal examination is usually feasible, sedation or anesthesia may be needed due to intense pain in some cases. 1

Critical Diagnostic Considerations During Examination

• Check for signs of chronicity including sentinel skin tag, hypertrophied anal papilla, fibrosis, or visible internal sphincter muscle at the fissure base. 2
• Assess fissure location carefully: off-midline, lateral, or multiple fissures should raise immediate suspicion for Crohn's disease, HIV, syphilis, herpes, anorectal cancer, tuberculosis, or other serious underlying conditions. 2, 3
• Look for associated perianal findings including surgical scars, anorectal deformities, other signs of perianal Crohn's disease, secondary cellulitis, or external fistula openings. 1

Common Pitfalls to Avoid

• Never perform forceful digital examination in an awake patient with severe anal pain, as this causes unnecessary trauma and does not change immediate management. 2
• Do not assume the diagnosis is straightforward if the patient has atypical features (off-midline location, lack of response to conservative treatment, or systemic symptoms), as these require urgent evaluation for underlying disease. 3
• Avoid delaying examination under anesthesia when office examination is inadequate, as this may delay diagnosis of serious conditions like abscess or malignancy. 1