Anorectal Disorders — Fissure, Fistula, Piles

A 50-year-old man presents with a 6-month history of itching and a palpable lump at the anal verge that appears during straining and retracts spontaneously. Anoscopy shows internal hemorrhoids above the dentate line. A 38-year-old woman with a 2-year history of recurrent anal pain, purulent drainage, and a visible opening in the perianal skin is diagnosed with an anal fistula on MRI. Which feature most reliably distinguishes internal hemorrhoids from an anal fistula?

A 32-year-old woman presents with severe anal pain during and after defecation for the past 3 weeks. She reports visible blood on toilet paper and describes the pain as "tearing" in nature. On examination, a visible tear is seen in the posterior midline of the anal canal. Digital rectal examination elicits severe pain, limiting full assessment. She denies any history of inflammatory bowel disease or trauma. What is the most appropriate first-line management?

Which of the following is the most common type of anal fistula based on the classification by Parks and Melnick?

Which of the following is the most common site of anal fissure?

A 48-year-old man with a 10-year history of chronic anal fissure (posterior midline) presents for surgical evaluation after failure of medical management with topical diltiazem and stool softeners for 8 weeks. On examination, the fissure has indurated edges, a sentinel pile at the anal verge, and an internal skin tag. Internal anal sphincter pressure is markedly elevated on manometry. He is concerned about postoperative incontinence. What is the most appropriate surgical intervention?