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HEMORRHOIDS AND ANORECTAL VARICES
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Hemorrhoids are rare in children and are divided into internal and external hemorrhoids. Internal hemorrhoids are masses of vascular tissue covered by rectal mucosa. They arise from the superior hemorrhoidal plexus and lie above the pectinate line (Figs. 411-1 and 411-2). External hemorrhoids are covered by skin and lie below the pectinate line. They arise from the inferior hemorrhoidal veins (Fig. 411-3). Most hemorrhoids in children are associated with chronic constipation and are of the external type. They appear as pearly gray or purple masses at the anal verge that may occasionally bleed. They may become firm and painful when thrombosed or infected. Incision and evacuation of thrombosed or infected hemorrhoids may be necessary, but stool softeners, warm sitz baths, and antibiotics are often sufficient therapy. Symptoms from hemorrhoids usually improve with treatment of underlying constipation.
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Anorectal varices form as a result of high-pressure portal venous circulation resulting in shunting of blood from the superior hemorrhoidal vein to the external iliac vein (systemic circulation). They are found beneath the rectal mucosa or in the anal canal. One-third of children with portal hypertension have hemorrhoids, 35% have anorectal varices, and 15% have isolated external anal varices. Occurrence is related to the duration and severity of portal hypertension. Rectal varices occasionally cause bleeding, but other symptoms are rare. Injection sclerotherapy or banding of varices is occasionally required in patients with severe portal hypertension and bleeding. Treatment via transjugular intrahepatic portosystemic shunt can be curative as well.
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Prolapse is the protrusion of 1 or all layers of the rectum through the anus. Isolated mucosal prolapse is common and appears as a red-purple, cylindrical protrusion from the anus of variable length, with radial folds extending from a central lumen at the leading point. Prolapsed mucosa may bleed and may secrete copious mucus. Anal pain may result from anal sphincter spasm. Children often complain of a mass in the anus after defecation that they cannot expel. Transient minor prolapse of rectal mucosa is common after defecation. Prolapse that includes mucosal, muscular, and serosal layers of the rectum (procidentia) is rare in childhood. It presents as a beefy red protrusion with circumferential folds caused by contractions of the circular musculature of the prolapsed rectum (Fig. 411-4).
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