Hemorrhoids and Other Anorectal Disorders
Nearly everyone has experienced anorectal discomfort. Our low-fiber diet, which results in small, hard stools; our lifestyle, which restricts the opportunities for defecation; and our erect posture, which promotes engorgement of the hemorrhoidal plexus all combine to make anorectal problems virtually ubiquitous. The anorectum also is the site of local manifestations of more generalized disorders, such as inflammatory bowel disease. Finally, because the rectum is a sexual organ for some people, sexually transmitted diseases may occur at that site.
I. HEMORRHOIDS
A. Pathogenesis.
Hemorrhoids are dilated veins within the anal canal and distal rectum. External hemorrhoids are derived from the external hemorrhoidal plexus below the dentate line and are covered by stratified squamous epithelium. Internal hemorrhoids are derived from the internal hemorrhoidal plexus above the dentate line and are covered by rectal mucosa.
Hemorrhoids are thought to develop in most instances as a consequence of erect posture, straining at stool, heavy lifting, or childbirth. In some patients, portal hypertension predisposes to hemorrhoids; rarely, hemorrhoids develop as a result of an intraabdominal mass.
B. Clinical presentation
1. History.
Hemorrhoids typically cause bleeding, which is detected as streaks of red blood on the stool and toilet paper. Patients also may complain of anal itching or pain. However, severe pain is an unusual symptom unless the hemorrhoid is thrombosed.
2. Physical examination.
Inspection of the anus may reveal bluish, soft, bulging veins indicative of external hemorrhoids or prolapsed internal hemorrhoids. Nonprolapsed internal hemorrhoids cannot be seen externally and are difficult to distinguish from mucosal folds by digital rectal examination unless they are thrombosed. Thrombosed hemorrhoids usually are exquisitely tender.
C. Diagnostic studies.
The anal canal and rectum should be examined by anoscopy and sigmoidoscopy. Symptomatic hemorrhoids usually are accompanied by varying degrees of inflammation within the anal canal. At sigmoidoscopy, the anus and rectum can be evaluated for other conditions in the differential diagnosis of rectal bleeding and discomfort, such as anal fissure and fistula, proctitis and colitis, rectal polyp, and cancer. Barium enema x-ray examination or colonoscopy should be performed in patients over age 50 and in patients of any age whose stool remains positive for occult blood after appropriate treatment for hemorrhoids.
D. Treatment.
A high-fiber diet, stool softeners, and avoidance of straining at stool and heavy lifting may be sufficient to treat mild hemorrhoidal symptoms. Warm baths twice a day and anal lubrication with glycerine suppositories provide further comfort. Addition of medicated suppositories, such as Anusol-HC (containing hydrocortisone), may help reduce associated inflammation. However, steroidcontaining medications should be limited to 2 weeks of continuous use to avoid atrophy of the anal tissues.
Additional treatment usually requires the expertise of a gastroenterologist or surgeon. Rubber-band ligation is usually the first definitive treatment. The procedure requires no anesthesia and produces excellent results in most patients.
Injection of hemorrhoids with sclerosing solutions, dilatation of the anal sphincter under anesthesia, electrocoagulation, and laser coagulation are alternatives if rubber banding is ineffective. In patients whose hemorrhoids are severe and refractory to these treatments, surgical excision of the hemorrhoidal plexus may be necessary. Rarely, surgical section of the internal anal sphincter is performed.
Injection of hemorrhoids with sclerosing solutions, dilatation of the anal sphincter under anesthesia, electrocoagulation, and laser coagulation are alternatives if rubber banding is ineffective. In patients whose hemorrhoids are severe and refractory to these treatments, surgical excision of the hemorrhoidal plexus may be necessary. Rarely, surgical section of the internal anal sphincter is performed.
II. ANAL FISSURES
A. Pathogenesis.
An anal fissure is a tear in the lining of the anus, usually resulting from the difficult passage of hard stool. Some fissures are a consequence of a more generalized bowel disorder, such as Crohn’s disease. Others result from the trauma of anal intercourse or insertion of foreign bodies. Rarely, carcinoma of the anus presents as an anal fissure.
More than 90% of fissures that are not associated with Crohn’s disease occur in the posterior midline. The remainder occurs in the anterior midline. Fissures associated with Crohn’s disease may occur at any location within the anal canal.
B. Clinical presentation.
Anal fissures are painful, and the pain is exacerbated by the passing of stool. The pain may lead to a cycle of retention of stool, formation of hard stool, passage of hard stool, and aggravation of the fissure. Bleeding and itching also are common. Anal fissures often coexist with hemorrhoids.
External examination by spreading the patient’s buttocks and anal orifice may reveal the fissure. Digital examination usually is quite painful for the patient and thus the rectal examination may be limited. Sometimes the fissure or a mass of granulation tissue can be palpated. Preliminary application of a topical anesthetic decreases the discomfort of the digital rectal examination and subsequent sigmoidoscopic examination.
C. Diagnostic studies
1. Anoscopy and sigmoidoscopy
should be performed to make the definitive diagnosis and to rule out other conditions mentioned in section I, in the discussion of hemorrhoids.
2. Scraping the fissure.
If the cause of the fissure is suspected to be sexual, a scraping of the fissure should be examined under dark field illumination to consider the possibility of a syphilitic lesion.
3. Radiologic evaluation.
Patients whose fissures fail to heal or who have fissures that are not in the midline should undergo radiologic evaluation of the large and small bowel for Crohn’s disease.
4.
The treatment of anal fissure is similar to that of hemorrhoids: high-bulk diet, stool softeners, warm baths, and lubricating suppositories. Most fissures heal on this regimen. Chronic anal fissures that are not due to inflammatory bowel disease may require dilatation of the anus, sphincterotomy, or excision of the fissure.
III. FISTULAS AND ABSCESSES