Internal hemorrhoids originate proximal to the dentate line and have visceral innervation. They commonly present with painless, bright red rectal bleeding after defecation. This results from the passage of stool over the thin-walled venules, causing abrasions and bleeding. Patients may also complain of a sensation of anal fullness from prolapse of the vessel.
External hemorrhoids originate distal to the dentate line, and since they have somatic innervation, they often cause significant pain. External hemorrhoids can also present with bright red rectal bleeding. Symptoms may also include swelling and pruritis. Thrombosis is much more common with external hemorrhoids and results in severe pain in the acute phase.
Factors contributing to hemorrhoid formation include constipation, obesity, increased intra-abdominal pressure from pregnancy or ascites, and family history. Differential diagnosis includes anorectal abscess, inflammatory bowel disease, malignancy, local trauma, herpes or other STI, rectal polyp, and rectal prolapse.
Management and Disposition
In the rare case of severe life-threatening bleeding, initiate fluid resuscitation and clamp or ligate the bleeding vessel. Otherwise, conservative treatment is recommended for initial management. Options include increased dietary fiber and fluid intake, warm sitz baths, and topical analgesics. Advanced cases may require surgical consultation and treatment. Emergency department treatment of thrombosed external hemorrhoids includes an elliptical excision and extrusion of the clot under local anesthesia.
Patients with other serious anorectal conditions may complain of “hemorrhoids.” Careful consideration of other potential causes of symptoms is critical.
Having the patient strain during the examination may reveal bleeding or prolapse of an internal hemorrhoid that might otherwise go unnoticed. Anoscopy can also be helpful.
Thrombosed hemorrhoids should not be excised in pregnant, immunocompromised, or pediatric patients.
External Hemorrhoids. Multiple engorged, thrombosed (dark blue hue) external hemorrhoids are seen in this patient with anal pain and bleeding. (Photo contributor: Lawrence B. Stack, MD.)
Evacuation of Thrombosed Hemorrhoid. (A) Painful 1.5-cm thrombosed hemorrhoid. (B) Infiltration with marcaine till blanches. (C) Clot delivery after incision. (D) Collapsed hemorrhoid after clot evacuation. (Photo contributor: Lawrence B. Stack, MD.)
Bleeding External Thrombosed Hemorrhoid. Engorged painful bleeding thrombosed hemorrhoids in a patient with chronic constipation. (Photo contributor: Department of Emergency Medicine, Naval Medical Center, Portsmouth, VA.)
Normal Distal Rectum Surface Anatomy. Columnar epithelium lines the colon (rectum), while squamous epithelium lines the anal canal and extends into the distal rectum. The columnar-squamous junction (interface) is termed the dentate line. The columnar epithelium is insensate, while the squamous epithelium is sensate. (Photo contributor: Philip E. Stack, MD.)