Constipation in adults
Author
Arnold Wald, MD Section Editor
J Thomas LaMont, MD Deputy Editor
Leah K Moynihan, RNC, MSN
Peter A L Bonis, MD
CONSTIPATION OVERVIEW — Constipation refers to a disturbance in bowel habits, but it has varied meanings. Stools may be too hard or too small, difficult to pass, or infrequent. Infrequent may be defined as fewer than three bowel movements per week. However, the frequent need to strain and a sense that the bowels are not empty are also common.
Constipation is a very common problem. Each year more than 2.5 million Americans visit their healthcare provider for relief from this problem.
CONSTIPATION CAUSES — Many factors can contribute to or cause constipation, although in most people, no single cause can be found. In general, constipation occurs more frequently as people get older. Many medical conditions can also cause constipation.
CONSTIPATION DIAGNOSIS — Your healthcare provider will ask about how frequently you move your bowels and how long you have felt constipated. In many cases, a diary of stool frequency and description is helpful. It is important to discuss any medications you take regularly since some can cause constipation (show table 1).
You may need a rectal examination as part of the physical examination. A rectal examination involves inserting a gloved finger inside the rectum to feel for any lumps or abnormalities. This test can also check for blood in the stool.
Diagnostic testing may be ordered in some situations, for example, if you have had a recent change in bowel habits, blood in the stool, weight loss, or a family history of colon cancer. Testing can include blood tests, x-rays, sigmoidoscopy, colonoscopy, barium enema, or more specialized testing if needed. (See “Patient information: Flexible sigmoidoscopy” and see “Patient information: Colonoscopy”).
CONSTIPATION COMPLICATIONS — Constipation is uncomfortable and can interfere with your quality of life. In addition, chronic constipation can be associated with other problems, including:
Aggravation of hemorrhoids (See “Patient information: Hemorrhoids”)
Fecal impaction (which can cause abdominal pain, nausea, vomiting, urinary retention, and ulcers in the rectum)
Anal fissures (painful tears in the anal canal that can be caused by passing a hard stool). (See “Patient information: Anal fissure”).
CONSTIPATION TREATMENT — The most important issues for treating constipation include understanding normal bowel function, eating foods high in fiber, and using laxatives or enemas if needed.
Behavior changes — The bowels are most active following meals, and this is often the time when stools will pass most readily. If you ignores your body’s signals to defecate, the signals become weaker and weaker over time.
By paying close attention to these signals, you may defecate more easily. Drinking a caffeine-containing beverage in the morning may also be helpful for stimulating a bowel movement.
Increase fiber — Increasing fiber in the diet may reduce or eliminate constipation. The recommended amount of dietary fiber is 20 to 35 grams of fiber per day. By reading the product information panel on the side of the package, you can determine the number of grams of fiber per serving (show figure 2). Many fruits and vegetables can be particularly helpful in preventing and treating constipation (show table 2A-2C). This is especially true of citrus fruits, prunes, and prune juice. Some breakfast cereals are also an excellent source of dietary fiber. (See “Patient information: High fiber diet”).
If you do not like high-fiber foods such as fruits, vegetables, and whole grains, you can mix psyllium powder in an 8-ounce glass of water or another beverage one to three times daily.
A number of other fiber supplements are also available. Examples include methylcellulose, wheat dextrin, and calcium polycarbophil (see “Bulk forming laxatives” below). You should increase the dose of fiber supplements slowly to prevent gas and cramping, and you should always take the supplement with an extra glass of fluid.
Fiber side effects — Consuming large amounts of fiber can cause abdominal bloating or gas; this can be minimized by starting with a small amount and slowly increasing until stools become softer and more frequent.
LAXATIVES — A variety of drugs and natural products are available for treating constipation. The choice between them is based upon how they work, how safe the treatment is, and the healthcare provider’s preferences.
In general, laxatives can be categorized into the following groups: (show table 3).
Bulk forming laxatives — These include natural fiber and commercial fiber preparations such as:
Psyllium (Konsyl®; Metamucil®; Perdiem®)
Methylcellulose (Citrucel®)
Calcium polycarbophil (FiberCon®; Fiber-Lax®; Mitrolan®).
Wheat dextrin (Benefiber®)
These work by increasing the water content and bulk of stool, which tends to decrease the time needed to pass through the colon.
Hyperosmolar laxatives — Hyperosmolar laxatives include:
Polyethylene glycol (MiraLax®, Glycolax®)
Lactulose
Sorbitol
These reduce water absorption from the colon, thereby wetting the stool. Stools usually become soft, but they are still formed. Lactulose and sorbitol are also digested by bacteria in the colon, which can produce gas and bloating. Sorbitol works as well as lactulose and is much less expensive. Polyethylene glycol is generally preferred since it does not cause gas or bloating and is available in the United States without a prescription.
Saline laxatives — Saline laxatives such as magnesium hydroxide (Milk of Magnesia®) and magnesium citrate (Evac-Q-Mag®) act similarly to the hyperosmolar laxatives (ie, they draw water into the colon).
Stimulant laxatives — Stimulant laxatives include senna (eg, Black Draught, ex-lax®, Fletcher’s® Castoria®, Senokot®) and bisacodyl (eg, Correctol®, Doxidan®, Dulcolax®).
Because of their effectiveness, stimulant laxatives can be overused. Excessive use of stimulant laxatives can cause side effects, including low potassium levels. Thus, you should take these drugs carefully if you must use them regularly. However, there is no convincing evidence that regular use of stimulant laxatives causes damages the colon, and they do not increase the risk for colorectal cancer or other tumors.
New treatments — Tegaserod (Zelnorm®) is a prescription medication for chronic constipation. It was taken off the market in the United States in March 2007 due to concerns about an increased risk of heart attack, stroke, and severe chest pain.
Lubiprostone (Amitiza®) is available for treatment of severe constipation in patients who have not responded to other treatments. It is a medication that increases intestinal fluid secretion. It is expensive compared to other agents but may be recommended if you do not respond to other medications.
Constipation treatments to avoid
Emollients — Emollient laxatives, principally mineral oil, soften stools by moisturizing them. They can be used as enemas if you have become impacted with stool. Taking mineral oil by mouth is not recommended, especially for older adults or if you have swallowing difficulties. If mineral oil is accidentally inhaled into the lungs, it can cause pneumonia. In addition, it can cause leakage of stool from the anus. Alternatives to mineral oil have fewer risks and equal benefit.
Stool softeners — Agents containing docusate (eg, Colace®) were previously thought to increase the fluid content of the stool, making it easier to pass. However, studies have subsequently shown that stool softeners are not effective in patients with constipation.
Natural products — A wide variety of natural products have been used for treating constipation. Some of them contain the active ingredients found in commercially available laxatives. However, their dose and purity may not be carefully controlled. Thus, these products are not generally recommended.
A variety of home-made enema preparations have been used throughout the years, such as soapsuds, hydrogen peroxide, and household detergents. These can be extremely irritating to the lining of the intestine and should not be used.
Pills, suppositories, or enemas — Laxative preparations are available as pills that are taken by mouth or as suppositories or enemas that are inserted into the rectum. In general, suppositories and enemas work more quickly compared to pills, but many people do not like using them.
Healthcare providers occasionally recommend prepackaged enema kits containing sodium phosphate/biphosphate (Fleet®) if you have not responded to other treatments. These are not recommended if you have problems with your heart or kidneys, and should not be used more than once unless directed by your healthcare provider.
BIOFEEDBACK FOR CONSTIPATION — Biofeedback is a behavioral approach that can be used by some people with severe chronic constipation. During defecation, the muscles of the pelvic floor and external anal sphincter should relax as a person bears down. Biofeedback can be helpful in treating people who involuntarily squeeze (rather than relax) these muscles (referred to as dyssynergic defecation)
A visual monitor is used to measure external anal sphincter pressures while bearing down. The patient watches the recordings of muscle activity and is asked to change their responses through trial and error [1] .
WHEN TO SEEK HELP FOR CONSTIPATION — You should speak with a healthcare provider about your constipation, especially if the problem:
Is new (ie, represents a change in your normal pattern)
Lasts longer than three weeks
Is severe
Associated with any other concerning features such as blood on the toilet paper, weight loss, fevers, or weakness
SUMMARY
Constipation refers to a problems with the bowels. It may mean that stools are too hard or too small, difficult to pass, or infrequent. Infrequent has been defined as fewer than three spontaneous bowel movements per week.
Things that can lead to constipation include a low fiber diet, inadequate fluid intake, being inactive (especially with disabled or older adults), and a number of medical conditions, including hypothyroidism (an underactive thyroid), pregnancy, irritable bowel syndrome, diabetes, multiple sclerosis, Parkinson disease, spinal cord injuries, and colon cancer. In addition, medications used for pain, muscle spasms, depression, mineral deficiencies, high blood pressure, and heart disease can often be associated with constipation.
Constipation is uncomfortable and can interfere with a person’s quality of life. In addition, chronic constipation can aggravate hemorrhoids, lead to fecal impaction (which can cause abdominal pain, nausea, vomiting, urinary retention, and ulcers in the rectum), or anal fissures (painful tears in the anal canal that can be caused by passing a hard stool).
Diagnostic testing may be ordered in certain situations. These include a recent change in bowel habits, blood in the stool, weight loss, or a family history of colon cancer. Testing can include blood tests, x-rays, sigmoidoscopy, colonoscopy, barium enema, or more specialized testing if needed.
Behavior changes and a high fiber diet benefit many patients with constipation. Laxatives should be used when behavior changes and fiber are ineffective.
Daily polyethylene glycol is recommended for patients who do not tolerate or respond to dietary fiber or fiber supplements.
Patients who do not respond to polyethylene glycol or sorbitol can use stimulant laxatives such as senna or bisacodyl two to three times per week as long as needed.
A patient should speak with their healthcare provider about constipation, especially if the symptoms are new (ie, represent a change in your normal pattern), last longer than three weeks, severe, or are associated with any other concerning features such as blood on the toilet paper, weight loss, fevers, or weakness.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.
National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute on Diabetes and Digestive and Kidney Diseases
(www.niddk.nih.gov)
The American Gastroenterological Association
(www.gastro.org)
The American College of Gastroenterology
(www.acg.gi.org)
[2-6]
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REFERENCES
1 Chiarioni, G, Whitehead, WE, Pezza, V, et al. Biofeedback is superior to laxatives for normal transit constipation due to pelvic floor dyssynergia. Gastroenterology 2006; 130:657.
2 Muller-Lissner, SA, Kamm, MA, Scarpignato, C, Wald, A. Myths and misconceptions about chronic constipation. Am J Gastroenterol 2005;100:232.
3 Corazziari, E, Badiali, D, Bazzocchi, G, Bassotti, G. Long term efficacy, safety, and tolerabilitity of low daily doses of isosmotic polyethylene glycol electrolyte balanced solution (PMF-100) in the treatment of functional chronic constipation. Gut 2000; 46:522.
4 Kamm, MA, Muller-Lissner, S, Talley, NJ, et al. Tegaserod for the treatment of chronic constipation: a randomized, double-blind, placebo-controlled multinational study. Am J Gastroenterol 2005; 100:362.
5 Wald, A. Is chronic use of stimulant laxatives harmful to the colon?. J Clin Gastroenterol 2003; 36:386.
6 Locke, GR III, Pemberton, JH, Phillips, SF. AGA technical review on constipation. Gastroenterology 2000; 119:1766.
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