Presented by Brandon Cheppa, MD
Chief Complaint: Bleeding per rectum
HPI: 5-year-old is brought in by his mother because of blood in his stool. She noticed it earlier this morning after her son had a bowel movement. The blood is bright red and streaked along the side of his feces, which are hard and brown. He is passing less stool than usual, having 1 bowel movement per day instead of 3. He has a “burning” anal pain every time he has a bowel movement. The patient does not want to eat because he is afraid to have a bowel movement, and he displays a posture to avoid putting weight on his buttocks. He denies any fever, vomiting, diarrhea, trauma, or any similar prior history.
ROS: As per HPI
Immunizations: Up to date
Family History: None
Social History: None
Examination of organ systems and body areas:
Vitals: HR: 84 RR: 18 T: 37.1 (Temporal)
General: Patient is active, playful, smiling, appearing well-hydrated. He is standing and anxious about anyone touching him.
Head: Normal scalp.
Ears: Normal tympanic membranes.
Eyes: Normal eyes. Normal conjunctivae.
Nose: Moist mucous membranes.
Neck: Supple. No lymphadenopathy.
Chest: Good air entry bilaterally. No added sounds. No retractions, or wheezing.
Cardiovascular: Good peripheral pulses. Normal heart sounds.
Abdomen: Flat, soft, nontender, Bowel sounds positive. No organomegaly.
Extremities: Nontender. No bruising. No swelling. Normal tone.
Skin: No rash.
Neurologic: Normal reflexes. No meningeal signs.
Genitourinary: External genitalia, normal male genitalia. Bilateral descended testes. No hernia.
Rectal: An examination shows a fissure at 12 o’clock and 7 o’clock. There was hard stool in the vault and the stool was guaiac negative. The anus was tender on digital exam.
1. When is an anal fissure considered chronic?
A. 2 weeks
B. 4 weeks
C. 6 weeks
D. 8 weeks
E. 10 weeks
2. Where is the most common location for an anal fissure in both males and females regardless of age?
A. anterior midline
B. anterior-lateral area
C. lateral line
D. posterior midline
E. posterior-lateral area
3. What is the most common cause of rectal bleeding in infancy?
A. anal fissure
B. infectious diarrhea
D. Meckel’s diverticulum
Anal fissures are the most common cause of painful rectal bleeding in the general population, and the most common cause of rectal bleeding in infants. They can occur at all ages, with predominance for people in their 20’s – 40’s.
Anal fissures are a superficial linear tear of the anal canal beginning at or just below the dentate line and extending distally to the anal opening. A chronic anal fissure has edematous tissue with a hypertrophied papilla proximally and a sentinel pile distally, which can be confused with an external hemorrhoid. This condition is painful due to the somatic sensory nerve fibers that supply the sensitive anal derm.
Greater than 90% of all anal fissures occur in the posterior midline of the anus. The second most common location is the anterior midline, and women have a higher chance of developing anterior fissures than men.
The proposed mechanism as to why anal fissures develop in the posterior midline is due to an injury that leads to irritation of the internal sphincter making it go into spasm, therefore increasing its tone. Because the blood supply enters laterally, the least perfused areas are the posterior and anterior portions of the sphincter and anal mucosa. This creates relative areas of tissue ischemia and impairs wound healing once damaged. Also, the posterior midline has weak skeletal muscle fibers that encircle the anus allowing the tissue to be injured by hard stool. This makes constipation a common cause of anal fissures, in addition to diarrhea and trauma. Constipation can also be a symptom of a patient with an anal fissure due to resisting the urge to defecate due to pain.
When a fissure is visualized in an uncommon location, such as in the lateral portions, systemic pathology or underlying infection should be suspected. Common causes of off midline fissures are Crohn’s disease, ulcerative colitis, cancers of the anus and rectum, extramammary Paget’s disease, leukemia, lymphoma, syphilis, Chlamydia, gonorrhea, tuberculosis and AIDS. Obtaining an appropriate history and recognizing abnormalities in the physical exam should aid in initiating the appropriate lab work to reach the underlying diagnosis. These patients should have cultures obtained from their anal canal, and be referred to a specialist for a biopsy of the ulcer’s edge.
Patients presenting with anal fissures describe having a sharp, cutting pain, during and right after defecation, and a dull ache that can linger for hours between bowel movements. They usually describe bright red blood, in small quantities, that is either streaked on their stool or on the toilet paper. The amount of blood is usually less than that seen with hemorrhoids. The history usually points to the diagnosis, and an examination of the anus is mandatory. A topical anesthetic might need to be applied due to pain that is caused when the buttocks are pulled apart, or when the anus is touched. On examination, noting any edema, skin tags, or sentinel piles will aid in finding the location of the anal fissure, and identification as to acute or chronic.
Treatment is gauged at providing symptomatic relief, decreasing anal sphincter spasm and preventing complications such as strictures. Treatment of acute anal fissures is the same as for hemorrhoids; recommend warm sitz baths for 15 minutes every 3-4 hours each day and after each bowel movement; making sure to clean the anus thoroughly. Also, add bran to their diet to make their stools soft and to prevent strictures. Adding a topical anesthetic such as lidocaine and hydrocortisone ointment will provide symptomatic relief. The mnemonic “WASH” is useful to remember this treatment; warm water, analgesia, stool softeners, and a high fiber diet. When followed, 60-90% of acute uncomplicated fissures will heal in 2-4 weeks.
A chronic anal fissure is one that is present for greater than 6 weeks. Treatment is the same, with the addition of medications aimed at decreasing the anal canals resting pressure by relaxing the sphincter. First line agents are nitroglycerin ointment, however, it can cause headaches. Nifedipine gel has similar efficacy to nitroglycerin, but has fewer side effects. Injecting botulinum toxin type A into the external sphincter is being used, and is superior to nifedipine and nitroglycerin in rates of healing, but should be considered when those agents fail. Even after medical management, 50% of these patients can relapse and require surgery such as dilation, sphincterectomy, or excision of fissures.
Filed under: Intern Report |