Anal Fistulas and Fissures Clinical Presentation

Updated: May 27, 2022
  • Author: Bruce M Lo, MD, MBA, RDMS, FACEP, FAAEM, FACHE, FAAPL, CPE; Chief Editor: Barry E Brenner, MD, PhD, FACEP  more...
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Anal fissures may present with rectal pain described as burning, cutting, or tearing that occurs with bowel movements. Spasm of the anus is very suggestive for an anal fissure. A history of constipation or passage of hard stools may be present. Typically, bright-red blood appears on the surface of stools, but blood usually is not mixed into stool and is present only in a small amount. Occasionally, blood is found on toilet paper after wiping. The patient may report no bleeding.

A patient with an anal fistula may complain of recurrent malodorous perianal drainage, pruritus, recurrent abscesses, fever, or perianal pain due to an occluded tract. Patients may report a recent perianal or buttock abscess. Pain occurs with sitting, moving, defecating, and even coughing. It usually is throbbing in quality and is constant throughout the day. Pain occasionally resolves spontaneously with reopening of a tract or formation of a new outflow tract.


Physical Examination

The physical examination of patients with fistulas or fissures begins by optimizing patient placement; place the patient in the left lateral decubitus position with knees drawn up toward the chest. [16] Examine the patient carefully to help avoid inflicting further pain or sphincter spasm. Rectal examination is generally difficult to tolerate because of sphincter spasm and pain. Examination may be facilitated by application of a topical anesthetic, such as lidocaine jelly, before digital rectal examination (DRE); however, a DRE may not be tolerated by some patients.

Most fissures are visible externally when the buttocks are gently spread apart. Having the patient bear down as if having a bowel movement may also help visualize an anal fissure. Acute fissures appear similar to a laceration, while a chronic fissure may be accompanied by external skin tags distally and hypertrophied anal papillae proximally. Most tears are found in the posterior midline. Acute fissures are erythematous and bleed easily.

With chronic fissures, the classic fissure triad may be seen, as follows:

  • Deep ulcer

  • Sentinel pile, which forms when the base of the fissure becomes edematous and hypertrophic (a resolving sentinel pile can result in a permanent skin tag or may become associated with a fistulous tract)

  • Enlarged anal papillae at dentate line, only seen in the OR under general anesthesia or if prolapsed

Bidigital rectal examination in a patient with a fistula-in-ano may reveal an indurated tract or cord. A fistula can be identified by small circles of granulation tissue, which exude pus when compressed if tissue is patent. A fistulous tract that opens internally can be visualized with the aid of an anoscope. Inguinal lymph nodes may be enlarged and painful.

If an abscess is also present with an anal fistula, cardinal signs of inflammation, rubor, dolor, calor, and tumor (eg, erythema, pain, increased temperature, edema) may be found.