Causes, Symptoms, Diagnosis & Treatment of Constipation

The list of signs and symptoms mentioned in various sources for Constipation includes the 32 symptoms listed below:

• Difficult bowel movement
• Dry bowel movement
• Painful bowel movement
• Dry feces
• Small feces
• Hard feces
• Absent bowel movement
• Infrequent bowel movement
• Fecal straining
• Abdominal pain
• Nausea
• Vomiting
• Weight loss
• Feeling uncomfortable
• Feeling sluggish
• Diarrhea - a blockage only allows liquid to pass
• Abdominal swelling
• Abdominal bloating
• Child constipation symptoms - some of the symptoms of children with constipation include:
  • Stomachache
  • Fecal incontinence - similar to diarrhea
  • Soiling underclothes
  • Refusal to go to the bathroom
  • Loss of appetite - such as in children holding back a bowel motion
  • Not eating much - despite being hungry
  • Hard stool
  • Holding back a bowel movement - there are various signs in children:
    • Squatting
    • Crossing legs
    • Clenching buttocks
    • Rocking
    • Red face

Constipation is a condition in which a person has uncomfortable or infrequent bowel movements.

Constipation may be acute or chronic. Acute constipation begins suddenly and conspicuously. Chronic constipation may begin gradually and persists for months or years.

A person with constipation often or always produces hard stools that may be difficult to pass. The rectum may not feel completely empty. Bowel movements are likely to be infrequent. Many people believe they are constipated if they do not have a bowel movement (defecate) every day. However, daily bowel movements are not normal for everyone, and having less frequent bowel movements does not necessarily indicate a problem unless there has been a substantial change from previous patterns. The same is true of the color and consistency of stool; unless there is a substantial change, the person probably does not have constipation. Constipation is blamed for many symptoms (such as abdominal discomfort, nausea, fatigue, and poor appetite—although constipation can cause nausea and poor appetite) that are actually the result of other disorders (such as irritable bowel syndrome and depression). People should not expect all symptoms to be relieved by a daily bowel movement.

Complications: Straining during a bowel movement increases pressure on the veins around the anus and can lead to hemorrhoids. Straining also increases blood pressure, which, although temporary, may be extreme.

Constipation is one of the major risk factors for the development of diverticular disease. The walls of the large intestine are damaged by the increased pressure required to move small, hard stools. Damage to the walls of the large intestine leads to the formation of balloon-like sacs or outpocketings (diverticula), which can become clogged and inflamed.

Fecal impaction, in which stool in the last part of the large intestine and rectum hardens and blocks the passage of other stool, sometimes develops in people with constipation. This condition is particularly common among older people, pregnant women, and people with an inactive colon (colonic inertia). Fecal impaction leads to cramps, rectal pain, and strong but futile efforts to defecate. Often, watery mucus or liquid stool oozes around the blockage, sometimes giving the false impression of diarrhea. Fecal impaction can aggravate or further worsen constipation.

Overconcern with regular bowel movements causes many people to abuse their bowels with laxatives, suppositories, and enemas. Overusing these treatments can actually inhibit the bowel's normal contractions and worsen constipation.

Causes

Constipation can result when the passage (transit) of stool through the large intestine is slowed by disease or certain drugs. Sometimes constipation is caused by dehydration or a low-fiber diet. Pain and mental disorders, such as depression, may also contribute to constipation. In many cases, however, the cause of constipation is unknown.

Slowed Transit of Stool: Constipation tends to occur when the passage of stool along the large intestine slows. Under normal circumstances, water is pulled from the stool as it passes through the large intestine. Slowed transit of stool allows the large intestine to pull more water from the stool, resulting in the hard, dry stools and difficult passage of stools that characterize constipation.

Disorders and diseases that can slow transit of stool include an underactive thyroid gland (hypothyroidism), high blood calcium levels (hypercalcemia), and Parkinson's disease. People with diabetes often develop a condition in which parts of the digestive system slow down. Other conditions, including poor blood supply to the large intestine and nerve or spinal cord injury, can also cause constipation by slowing transit.

In an extreme case of slowed transit, called colonic inertia, the large intestine stops responding to the stimuli that usually cause bowel movements: eating, a full stomach, a full large intestine, and stool in the rectum. A decrease in contractions in the large intestine or an insensitivity of the rectum to the presence of stool results in severe, chronic constipation. Colonic inertia often occurs in people who are older, debilitated, or bedridden, but it occasionally occurs in otherwise healthy younger women (and, much less commonly, in healthy younger men). Colonic inertia sometimes occurs in people who habitually delay moving their bowels or who have used laxatives or enemas for a long time.

Dehydration and Low-Fiber Diet: Dehydration causes constipation because the body tries to conserve water in the blood by removing additional water from the stool. Lack of fiber (the indigestible part of food) in the diet can lead to constipation because fiber helps hold water in the stool and increases its bulk, making it easier to pass.

Obstruction: Constipation is sometimes caused by obstruction of the large intestine. Obstruction can be caused by cancer, especially in the last portion of the large intestine, if a tumor blocks the movement of stool. People who previously had abdominal surgery may develop obstruction, usually of the small intestine, because of formation of bands of fibrous tissues (adhesions), which impede the flow of the stool.

Dyschezia: Dyschezia is difficulty in defecating caused by an inability to control the pelvic and anal muscles. Having a normal bowel movement requires relaxing the pelvic floor muscles (the muscles that support the bladder, uterus, and rectum) and the circular muscles (sphincters) that keep the anus closed. Otherwise, efforts to defecate are futile, even with severe straining. People with dyschezia sense the need to have a bowel movement but cannot. Even stool that is not hard may be difficult to pass.

Conditions that can cause dyschezia include pelvic floor dyssynergia (a disturbance of muscle coordination), anismus (a failure of the sphincter muscles to relax during defecation), rectocele (hernia of the rectum into the vagina), enterocele (bulging of the small intestine and the lining of the abdominal cavity between the uterus and the rectum or between the bladder and the rectum), rectal ulcer, and rectal prolapse (protrusion of the rectal lining through the anus).

Aging: Constipation is particularly common among older people. Age-related changes in the large intestine (see Biology of the Digestive System: Large Intestine and Rectum) along with increased use of drugs, a low-fiber diet, and reduced physical activity tend to slow the transit of stool through the large intestine. Slowed transit is particularly common during periods of illness. The rectum enlarges with age, and increased storage of stool in the rectum allows hard stool to become impacted.

Pain and Psychologic Factors: Chronic pain and psychologic conditions, especially depression, are common causes of acute and chronic constipation. Changes in the levels of certain substances in the brain, such as serotonin, can affect the intestinal tract.

Evaluation

When constipation develops in someone who has not had it before, the doctor first looks for an easy explanation, such as a change in diet or physical activity or new use of a drug known to cause constipation. Then, the doctor may perform blood tests to check for an underactive thyroid gland (hypothyroidism) or high calcium levels in the blood (hypercalcemia), both of which can cause constipation. If there is any question about cancer as a cause, a colonoscopy is performed.

Prevention

Constipation is best prevented and treated with a combination of exercise, a high-fiber diet, an adequate intake of fluids, and the occasional use of laxatives. When a potentially constipating drug has been prescribed, a laxative along with increased intake of dietary fiber and fluids help to prevent constipation.

Vegetables, fruits, and bran are excellent sources of fiber. Many people find it convenient to sprinkle 2 or 3 teaspoons of unrefined miller's bran on high-fiber cereal or fruit 2 or 3 times a day. To work well, fiber must be consumed with plenty of fluids.

Treatment

When an underlying disorder is causing constipation, the disorder must be treated.

Dyschezia is not easily treated with laxatives. Relaxation exercises and biofeedback are effective for some people with pelvic floor dyssynergia. Surgery may be needed to repair an enterocele or a large rectocele.

Fecal impaction cannot be treated by modifying the diet or simply by taking laxatives. The hard stool usually has to be removed by a doctor or nurse using a gloved finger. Often an enema is given after the hard stool is removed.

Overzealous treatment, especially the long-term use of stimulant laxatives, irritant suppositories, and enemas, can lead to diarrhea, dehydration, cramps, or dependence on laxatives.

Laxatives: Many people use laxatives to relieve constipation. Some laxatives are safe for long-term use; others should be used only occasionally. Some are good for preventing constipation, others for treating it.

Bulking agents, such as bran and psyllium Some Trade Names
METAMUCIL
(also available in the fiber of many vegetables), add bulk to the stool. The increased bulk stimulates the natural contractions of the intestine, and bulkier stools are softer and easier to pass. Bulking agents act slowly and gently and are among the safest ways to promote regular bowel movements. These agents generally are taken in small amounts at first. The dose is increased gradually until regularity is achieved. People who use bulking agents should always drink plenty of fluids. These agents may cause problems with increased gas (flatulence).

Stool softeners, such as docusate Some Trade Names
COLACE
, increase the amount of water that the stool can hold. Actually, these laxatives are detergents that decrease the surface tension of the stool, allowing water to penetrate the stool more easily and soften it. In addition, the slightly increased bulk that results from these drugs stimulates the natural contractions of the large intestine and thus promotes easier elimination. Some people, however, find the softened nature of the stool unpleasant. Stool softeners are best reserved for people who must avoid straining, such as people who have hemorrhoids or have recently had surgery.

Osmotic agents pull large amounts of water into the large intestine, making the stool soft and loose. The excess fluid also stretches the walls of the large intestine, stimulating contractions. These laxatives consist of salts or sugars that are poorly absorbed. They may cause fluid retention in people who have kidney disease or heart failure, especially when given in large or frequent doses. Osmotic agents that contain magnesium and phosphate are partially absorbed into the bloodstream and can be harmful to people who have kidney failure. Although a rare occurrence, phosphate laxatives taken by mouth have caused kidney failure. These laxatives usually work within 3 hours. They are also used to clear stool from the intestine before x-rays of the digestive tract are taken or before a colonoscopy is performed.