Facts on File Encyclopedia of Health and Medicine

The most common cause of anal fissure is CONSTIPA-
TION, in which the bowel movement is hard and
often forced. PAINcan be intense with bowel move-
ments. The doctor can diagnose anal fissure on the
basis of the symptoms and by examining the anal
area, though may perform an anoscopy to examine
the inner anus. Most anal fissures heal with conser-
vative treatment that includes frequent sitz baths,
topical application of hydrocortisone preparations
to reduce INFLAMMATION, high-fiber diet and stool
softeners to pull more moisture into the stools, and
daily physical exercise such as walking to improve
intestinal motility (movement of food through the
gastrointestinal tract) and encourage regular bowel
movements.
The next level of treatment for anal fissure that
persists is topical nitroglycerin or topical nifedipine
(a calcium channel blocker), both of which
increase blood flow to the anal sphincter and
cause it to relax. Doctors prescribe these medica-
tions in oral form to relax the CORONARY ARTERIESas
a treatment for CORONARY ARTERY DISEASE(CAD); the
pharmacological action on the blood vessels in the
anal area is similar. Nitroglycerin ointment, like
other forms of nitroglycerin, can cause HEADACHE
and dizziness. Another treatment option is BOTU-
LINUM THERAPY, in which the doctor injects the anal
sphincter near the fissure with botulinum toxin to
temporarily paralyze the MUSCLE fibers, which
relaxes the sphincter. The effect of the botulinum
toxin lasts about three months. Extensive anal
tears and fissures that do not heal with other
treatments may require surgical repair. INFECTION
may develop with persistent or extensive anal fis-
sure, and requires appropriate antibiotic therapy.
See also ENDOSCOPY; HEMORRHOIDS; PROCTITIS; SITZ
BATH.

antacids Products that neutralize gastric (STOM-
ACH) acid to relieve DYSPEPSIA(heartburn and indi-
gestion). Antacids work by increasing the pH (acid
level) of the gastric juices, which reduces the irri-
tation to the stomach tissues. Most antacids con-
tain mineral salts, which are alkaline.
Because of their high salt and mineral content,
many antacids can cause CONSTIPATIONor DIARRHEA
by drawing excessive fluid from the gastrointesti-
nal tract. Sodium bicarbonate, which most people
mix at home by dissolving baking soda in water,

has such a high sodium level that it can affect

BLOOD PRESSUREand the rhythm of the HEART. Any-

one who has CARDIOVASCULAR DISEASE(CVD), espe-

cially HYPERTENSIONor ARRHYTHMIA, should not use

sodium bicarbonate as an antacid.

COMMON ANTACID PRODUCTS

Active Ingredient Representative Products

aluminum hydroxide ALternaGEL

aluminum/magnesium combination Maalox, Mylanta

bismuth subsalicylate Pepto-Bismol

calcium carbonate Tums, Titralac

magnesium hydroxide milk of magnesia

simethicone Gas-X, Phazyme

sodium bicarbonate baking soda

Aluminum hydroxide, though very effective at

neutralizing stomach acid, is so likely to cause

constipation that it nearly always is combined

with magnesium, which has the opposite effect.

Doctors may recommend magnesium-based

antacids, such as milk of magnesia, as LAXATIVESto

treat mild, occasional constipation. Many antacid

products also contain simethicone, a surfactant

that breaks up intestinal gas bubbles to relieve

bloating and FLATULENCE.

Bismuth subsalicylate products such as

Pepto-Bismol contain an aspirin-like

ingredient that can cause the rare but

serious SIDE EFFECT, REYE’S SYNDROME, in

children who have viral infections. Chil-

dren should not take these products.

Antacids are available over the counter, with-

out a doctor’s prescription. Occasional use of

antacids can provide rapid relief of dyspepsia and

other digestive discomforts. Antacids are most

effective taken with food, which increases the

time the antacid remains in the stomach, and liq-

uid forms seem to be more effective than chew-

able forms. Chronic or regular use of antacids can

result in numerous health problems, ranging from

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