Laxatives for Constipation

Individuals should consult their physicians before using laxatives or stool softeners.

Constipation is characterized by infrequent bowel movements that are painful or difficult or stools that are hard in consistency. Irregular bowel movements alone are not a reliable indicator of constipation because bowel frequency can vary between three times a day to once a week among normal individuals. Hard stools that are difficult to pass or infrequent stools accompanied by abdominal pain, back pain, and abdominal bloating define constipation.

There are many causes of constipation including:

• Diets are low in fiber. Fiber is a vegetable material resistant to digestion that promotes soft stools by adding bulk to the stool and causing water to be retained in the stool.
• Side effects of medications such as narcotic painkillers, antidepressants, iron supplements, calcium channel blockers (medications for high blood pressure), and certain types of antacids.
• Narrowing or blockage of the large intestine (colon) due to scarring from previous surgery, colon cancer, or advanced diverticulosis.
• Ineffective contraction or spasm of the colon's muscles due to irritable bowel syndrome (IBS) or other diseases of the colon's muscles.
• Hormonal (endocrine) disturbances such as an underactive thyroid gland (hypothyroid) and diabetes mellitus with nerve damage.
• Neurologic conditions such as Parkinson's disease, multiple sclerosis, and others.

Examples of common medications that can cause constipation:

• Narcotic pain medications: codeine (Tylenol #3), oxycodone (Percocet), hydromorphone (Dilaudid), and others
• Antidepressants: amitriptyline (Elavil, Endep), fluoxetine (Prozac), and imipramine (Tofranil)
• Anticonvulsants: phenytoin (Dilantin) and carbamazepine (Tegretol)
• Iron supplements
• Calcium channel blockers, for example, diltiazem (Cardizem) and nifedipine (Procardia)
• Antacids, for example, aluminum hydroxide (Amphojel) and aluminum carbonate (Basaljel)

Mild constipation without an underlying cause (such as medications, an underactive thyroid, or colon obstruction) can often improve with lifestyle modifications that include:

1. Increase fiber in the diet. Fiber improves bowel function by adding bulk and softening the stool. You can increase the fiber in your diet with foods or over-the-counter (OTC) fiber supplements.
2. Increase fluid intake. Although this is widely recommended as a treatment for constipation, no studies are showing that increasing fluids improves constipation.
3. Regular exercise such as walking, swimming, or running. Similar to increasing fluid intake, although exercise is widely recommended for treating constipation, there are no studies demonstrating its value for constipation.

Many foods can act as natural laxatives. These foods are high in fiber and can help get things moving, for example:

• Seeds, for example, flax, chia, and pumpkin
• Raisins, figs, and prunes
• Vegetables, for example, sweet potatoes, greens (spinach, kale), and pumpkin
• Fruits (including the skin)
• Whole-grain bread and cereals
• Whole beans (such as kidney beans and pinto beans)
• Oat bran
• Corn
• Barley

Laxatives are medicines that increase the frequency and ease of passing stool. Many types of laxatives are available over-the-counter (OTC) for the relief of mild, occasional constipation. If constipation becomes moderate to severe or does not respond to OTC products, consult a doctor.

Most OTC laxatives are safe, effective, and well-tolerated. There are distinct types of laxatives that function differently and have varying degrees of effectiveness and potential side effects. Talk to your doctor about the best laxative for your needs.

If an infant is younger than four months old and seems constipated, contact the child's pediatrician. For older children, home remedies including dietary modifications may help relieve constipation. If a child has been constipated for a short time, changing the diet may be the only treatment needed. It is common for infants to become constipated when they transition to solid foods, and often adding fiber to the diet can ease constipation.

The following natural treatments may be used for infants older than four months of age, or children with constipation:

• Dark corn syrup (Karo syrup) contains complex sugar proteins that keep water in the bowel movement. One teaspoon per four ounces of formula or expressed breast milk until the infant has a bowel movement.
• Prune or apple juice works best to treat constipation in children. Four ounces/day for children 4 months to 1 year of age.
• High-fiber foods. If your infant is eating solid foods, barley cereal may be used. Other high-fiber fruits and vegetables (or purés), including apricots, sweet potatoes, pears, prunes, peaches, plums, beans, peas, broccoli, or spinach can be fed to the child.
• Your doctor may recommend increased fiber in the child's diet, through supplementation.
• In infants with acute or recurrent constipation, glycerin suppositories or rectal stimulation with a lubricated rectal thermometer may be used to move hard stools. These methods should not be used often because they may cause irritation or tolerance. Infants older than 6 months with recurring constipation despite dietary changes may be treated with osmotic laxatives, such as polyethylene glycol (PEG) without electrolytes (polyethylene glycol 3350, for example, Miralax), lactulose, or sorbitol. Do not use stimulant laxatives (for example, senna, bisacodyl), mineral oil, and enemas in infants because they may have unwanted side effects.

Parents or caregivers should contact the physician immediately if the child has severe abdominal pain, swollen or bloated abdomen, rectal pain, or bleeding. If there are any concerns about the child's bowel habits or questions about diet, parents or caregivers should talk to their child's pediatrician.

Hormones from pregnancy, as well as prenatal vitamins and iron supplements, may cause constipation. Pressure from the uterus pushes on the bowels and can cause constipation.

Dietary and behavioral modifications can ease constipation during pregnancy and are considered safe. It's best to try these natural remedies first to treat constipation during pregnancy.

• Eat a diet rich in fiber with whole grains, fruits, and vegetables.
• Supplement fiber in the diet with over-the-counter products such as Metamucil, which is considered safe
• Stay hydrated -- drink at least 6-8 glasses of water per day
• Drink 1-2 glasses of prune juice per day
• Exercise regularly -- if permitted by your obstetrician

Pregnant women should talk with their doctor before using over-the-counter laxatives or stool softeners during pregnancy. Laxatives can cause fluid loss and diarrhea, so it is important not to overuse them during pregnancy. Avoid cod liver oil as a treatment for constipation if you are pregnant because it may prevent the absorption of needed vitamins and minerals.

Stimulant laxatives are fast-acting laxatives that induce bowel movements by increasing the contraction of muscles in the intestines and are effective when used on a short-term basis. Examples of stimulant laxatives include:

• Aloe
• Cascara
• Senna compounds
• Bisacodyl
• Castor oil

Bisacodyl: Bisacodyl (Dulcolax, Correctol) is available over-the-counter in oral pill form and as a suppository or enema. The oral form takes 6 to 10 hours to work. Bisacodyl is commonly used in cleansing the colon for colonoscopies, barium enemas, and intestinal surgeries. While effective for occasional constipation, bisacodyl should not be taken for more than a week, and a doctor should supervise repeated use.

Senna, cascara sagrada, and casanthranol: Other stimulant laxatives include senna (Ex-Lax, Senokot), cascara sagrada (Nature's Remedy), and casanthranol. These laxatives are converted by the bacteria in the colon into active compounds, which then stimulate the contraction of colon muscles. After taking these products orally, bowel movements occur quickly, after only 8 to 24 hours. Prolonged, chronic use of these laxatives can cause the lining of the colon to become darker than normal (melanosis coli) due to the accumulation of a pigment (melanin).

Castor oil: Castor oil (an ingredient of Purge Concentrate) is a liquid stimulant laxative that works in the small intestine. It causes the accumulation of fluid in the small intestine and promotes evacuation of the bowels. Castor oil should not be taken with food, although juice or other flavored liquids can help hide its unpleasant taste. This laxative works rather quickly, usually within 2 to 6 hours. Castor oil is usually used to cleanse the colon for surgery, barium enema, or colonoscopy. The absorption of nutrients and minerals by the small intestine can be impaired by the frequent use of castor oil. This medicine is not recommended for the repeated treatment for constipation.

Precautions for stimulant laxatives

• The intensity of the action of stimulant laxatives is dose-related. A large dose of any stimulant laxative can produce serious adverse effects.
• Side effects include severe cramps, excess fluid loss and dehydration, blood electrolyte disturbances such as low levels of blood potassium (hypokalemia), and malnutrition with chronic use.
• There is concern that chronic, long-term use of stimulant laxatives can lead to loss of colon function (cathartic colon). After years to decades of frequent use of stimulant laxatives, the nerves of the colon slowly disappear, the colon muscles wither, and the colon becomes dilated. Consequently, constipation may become increasingly worse and unresponsive to laxatives. It is not clear, however, which comes first; a progressive decrease in colon function that leads to the use of stimulant laxatives, or the use of laxatives that leads to a decrease in colon function. Nevertheless, long-term use of stimulant laxatives usually is reserved for use after other treatments have failed.

Stool softeners called emollient laxatives, prevent the hardening of the feces by adding moisture to the stool. The active ingredient in most stool softeners is a medicine called docusate. Agents containing docusate do not by themselves stimulate or increase the number of bowel movements. They are used more to prevent constipation than to treat it.

Stool softeners are commonly recommended for individuals who should avoid straining while defecating, including those:

• Who are recovering from abdominal, pelvic, or rectal surgery, childbirth, or heart attack
• With severe high blood pressure or abdominal hernias
• With painful hemorrhoids and/or anal fissures

Softening the stool in these affected individuals can help reduce pain during defecation.

Stool softeners available OTC include:

• Colace
• Surfak
• Pharmacy or store-branded products containing docusate

Some preparations (for example, Peri-Colace) combine a stool softener with a stimulant laxative to activate bowel movements.

What are the pros of using stool softeners?

Stool softeners are generally safe and well-tolerated.

What are the precautions for using stool softeners?

They should not be combined with mineral oil, a lubricant laxative, because stool softeners may increase the absorption and toxicity of mineral oil. Mineral oil droplets absorbed into the body can deposit and cause inflammation in the lymph glands, liver, and spleen.

Bulk-forming laxatives are the most commonly recommended initial treatments for constipation as they tend to be the most gentle. Bulk-forming laxatives may work as quickly as 12 hours or take as long as three days to be effective. Some bulk-forming laxatives are derived from natural sources such as agar, psyllium, kelp (alginates), and plant gum. Others are synthetic cellulose compounds such as methylcellulose and carboxymethylcellulose. Natural and synthetic bulk-forming laxatives act similarly. They dissolve or swell in the intestines, lubricate and soften the stool, and make the passage of stool easier and more frequent.

Examples of bulk-forming laxatives include:

• Methylcellulose (Citrucel)
• Psyllium hydrophilic mucilloid (Metamucil)
• Polycarbophil (FiberCon)
• Guar gum (Benefiber)
• Malt soup extract (Maltsupex).

Many of these agents are available as powders and are mixed with fluids. Fruit drinks, fruit juice, and soft drinks mask the gritty taste of these laxatives better than water. Some are available as wafers, which are designed to be eaten with a separate beverage.

What are the pros of using bulk-forming laxatives?

• Bulk-forming laxatives are not absorbed from the intestines into the body and are safe for long-term use. They are also safe for elderly patients with constipation.
• They are helpful in patients with irritable bowel syndrome (IBS), diverticulosis, and colostomies.
• Some bulk-forming laxatives (such as guar gum) are used as fiber supplements in patients whose diets contain insufficient fiber. High fiber consumption can help control weight gain and sometimes modestly lower the level of cholesterol in the blood.

What are the precautions for using bulk-forming laxatives?

• Each dose of a bulk-forming laxative should be taken with at least a full glass (8 ounces) of fluid to be safe and effective. Bulk-forming laxatives may not be appropriate for individuals who must restrict oral fluid intake (such as patients with kidney failure).
• Individuals with narrowing of the digestive tract (including esophageal stricture, intestinal stricture, or severe adhesions from previous surgery) should not use bulk-forming agents without their doctors' approval due to the risk of blockage of the intestine or the esophagus.
• Some individuals may be allergic to the laxative or other substances contained in the product, such as coloring or artificial sweeteners.
• Abdominal bloating, discomfort, and flatulence (gas) can be bothersome to some people using bulk-forming laxatives. By trying different types of bulk-forming laxatives, it usually is possible to find one that does not cause discomfort.
• Some of these products contain sugar. People with diabetes mellitus may need to select sugar-free bulk-forming laxatives.
• Bulk-forming laxatives can decrease the absorption of certain medications such as aspirin, warfarin (Coumadin, Jantoven)), and carbamazepine (Tegretol) and can also reduce blood sugar levels.

Mineral oil (liquid petrolatum) coats and softens the stool. Like stool softeners, mineral oil is used by patients who need to avoid straining (for example, after hernia repair, hemorrhoid surgery, heart attacks, and childbirth).

What are the precautions for using lubricant laxatives?

• Mineral oil should be avoided in individuals taking blood thinners, such as warfarin (Coumadin). Mineral oil decreases the absorption of vitamin K (important in forming clotting factors in the blood) from the intestines. The decreased absorption of vitamin K in patients taking warfarin can potentially lead to "over-thinning" of the blood and increase the risk of excessive bleeding.
• Mineral oil should not be taken during pregnancy since it may inhibit vitamin absorption and decrease the availability of vitamin K to the fetus.
• Mineral oil can cause pneumonia if it leaks into the lungs. The leakage of secretions and other contents from the mouth and the esophagus into the lungs is called aspiration. Certain individuals (for example, the very young, the elderly, stroke victims, and those with swallowing difficulties) are prone to aspirate, especially while lying down. Therefore, mineral oil should not be given at bedtime or to individuals who are prone to aspirate.
• Mineral oil should only be used for short periods. Significant absorption of mineral oil into the body can occur if used repeatedly over prolonged periods.

• The active ingredients in saline laxatives are mostly magnesium, sulfate, citrate, and phosphate ions. These ions draw water into the intestines. The additional water softens the stool, increases pressure within the intestines, and increases intestinal contractions resulting in the discharge of softer stool. Fleet Phospho-Soda, milk of magnesia, and magnesium citrate are examples of saline laxatives.
• Oral doses of saline laxatives should be taken with one to two 8-ounce glasses of water. The onset of bowel response is usually 1/2 to 3 hours after consuming the laxative. Small doses are sometimes recommended for the treatment of occasional constipation, while larger doses can produce complete evacuation of the intestine. Complete cleansing of the bowel is useful in preparing for colonoscopy, sigmoidoscopy, and barium enema.
• The active ingredient in osmotic-type laxatives such as GoLYTELY, GlycoLax, and MiraLax is polyethylene glycol (PEG). These work by holding water in the stool to soften the stool and increase the number of bowel movements. Osmotic-type laxatives are often used to cleanse the bowel before colonoscopies or colon surgery.

Precautions for saline and osmotic laxatives

• Since there may be some absorption of the active ingredients from the intestines into the blood circulation, saline laxatives should not be used in certain individuals. Individuals with impaired kidney function should not use laxatives containing magnesium or phosphate salts. Excess accumulation of magnesium and phosphate in the blood of these individuals can lead to toxicity. Those who need to limit their sodium intake, such as those with congestive heart failure, kidney disease, and high blood pressure, should not use laxatives that contain sodium.
• Side effects of osmotic-type laxatives include nausea, abdominal cramping, or gas.
• People who have a history of abdominal surgery or bowel obstruction should consult their doctor before using this medication.
• Caution is advised when using this drug in the elderly because they may be more sensitive to its side effects, especially diarrhea.

Rectally administered enemas and suppositories are commonly used to cleanse the rectum and the sigmoid colon (the part of the colon closest to the rectum) before surgery, childbirth, and flexible sigmoidoscopy. Enemas and suppositories are used to relieve constipation and rectal fecal impaction (blockage of the rectum by hard, compacted stool). They can also be used in conjunction with oral laxatives in cleansing the colon in preparation for barium enema studies. Some suppositories contain stimulant laxatives.

Enemas and suppositories include docusate (Microenema), bisacodyl (Dulcolax Suppository), and sodium phosphate (Fleet Enema). These products are intended for occasional use and are not recommended as a chronic laxative regimen unless directed by a physician.

Individuals should carefully follow instructions in using enemas. The person should lie on the left side with the knees bent. The enema solution should be inserted slowly into the rectum. The person should retain the solution in the rectum until definite rectal pressure and the urge to have a bowel movement are felt. Evacuation usually occurs within minutes to an hour.

Precautions for using enemas and suppositories

• Soapsud enemas can cause rectal irritation and sometimes rectal gangrene and are not recommended.
• Enema solutions can cause fluid and electrolyte disturbances in the blood if used on a chronic basis.

Many people have a life-long tendency toward constipation while others have occasional constipation alternating with a normal bowel pattern or even diarrhea.

While mild and intermittent constipation in these individuals is usually not a cause for concern, a doctor should be consulted under the following circumstances:

• New onset of constipation or recent change in bowel habits
• Moderate to severe constipation, or constipation that does not respond to self-treatment with simple bulking agents that provide fiber
• Constipation that is accompanied by rectal bleeding, abdominal pain and cramps, nausea and vomiting, or involuntary weight loss
• Constipation during pregnancy or while breastfeeding.

Laxatives are not intended as weight loss supplements. It may seem as if you lost weight once a laxative has taken effect and your constipation is relieved, but by the time stool reaches the large intestine (colon), most of the fat and calories from your food have already been absorbed by the small intestines. What you do lose is water, electrolytes, minerals, and indigestible fiber. Any "water weight" you may lose comes back as soon as you drink fluids.

Laxative abuse occurs when people frequently take laxatives to lose weight. Often, laxatives are taken after binge eating in an attempt to purge calories. This is part of an eating disorder called bulimia. There are serious health consequences to laxative abuse, including life-threatening complications. Laxatives deplete the body of needed electrolytes and minerals, which the body needs. This can lead to malfunctions in your vital organs. Dehydration caused by laxative abuse can lead to tremors, fainting, kidney damage, and even death.

When people use laxatives consistently, dependence can develop and the colon stops working the way it should, and it can take larger and larger doses of laxatives to result in bowel movements. Chronic abuse of laxatives can increase the risk of developing colon cancer.

If you are abusing laxatives in the hope of losing weight, or if you think you may be addicted to laxatives, talk to your doctor to get help.