Differential Diagnosis for Sharp Anal Pain

• Single most likely diagnosis
  • Anal fissure: This is the most common cause of sharp anal pain, especially during and after defecation. The pain is often severe and can be accompanied by bleeding.
• Other Likely diagnoses
  • Hemorrhoids: Although typically causing a dull ache, thrombosed external hemorrhoids can cause sharp pain, especially if they become strangulated.
  • Proctalgia fugax: A condition characterized by sudden, severe anal pain that lasts for seconds or minutes, often at night.
  • Anal abscess: An infected cavity filled with pus near the anus, which can cause sharp pain, swelling, and redness.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Rectal cancer: Although less common, rectal cancer can cause sharp anal pain, especially if the tumor is large or has invaded surrounding structures.
  • Necrotizing fasciitis: A rare but life-threatening infection of the skin and soft tissues, which can cause severe pain, swelling, and redness around the anus.
  • Ischiorectal abscess: A type of abscess that can cause severe pain, swelling, and redness in the ischiorectal fossa, which can lead to sepsis if left untreated.
• Rare diagnoses
  • Levator ani syndrome: A condition characterized by chronic pain and tenderness in the levator ani muscle, which can cause sharp anal pain.
  • Coccygodynia: Pain in the coccyx (tailbone) area, which can radiate to the anus and cause sharp pain.
  • Pudendal neuralgia: A condition characterized by chronic pain in the distribution of the pudendal nerve, which can cause sharp anal pain.