Cascara For Constipation

Constipation

"I'm constipated" - What does that mean?

Not all people mean the same thing when they use the term "constipation." In general, "constipation" refers to infrequent or difficult bowel movements. An individual person's specific symptoms may differ from another's, and may include achieving a bowel movement only every several days, experiencing difficulty passing stool, having to strain excessively during a bowel movement, not feeling like a bowel movement has been complete, passing hard stool, spending too much time trying to have a bowel movement, needing to use one's hands to help stool come out, and trying but failing to have a bowel movement.1-3

It is important for patients and doctors to communicate clearly about what patients mean by "constipation." There may be a tendency to focus on how often a person achieves bowel movements, with at least 3 bowel movements per week being considered "normal." But many times patients are bothered by the multiple symptoms of difficult stool passage, even if they achieve several bowel movements per week or even every day.

Formal definitions of constipation

The American College of Gastroenterology Chronic Constipation Task Force recommended a broad definition of constipation that captures the symptoms of patients who report that they are constipated:1, 4

"Constipation is a symptom-based disorder defined as unsatisfactory defecation ["defecation" is the passing of stool] and is characterized by infrequent stools, difficult stool passage, or both. Difficult stool passage includes straining, a sense of difficulty passing stool, incomplete evacuation, hard/lumpy stools, prolonged time to stool, or need for manual maneuvers to pass stool. Chronic constipation is defined as the presence of these symptoms for at least 3 months."

Most of the time, there is no specific explanation for constipation, and it is considered "functional, " meaning that symptoms are present without a clear underlying abnormality. Leading researchers have met periodically in Rome since the 1980s, and have proposed symptom-based criteria for the functional gastrointestinal disorders. The Rome III definition of functional constipation, proposed in 2006, is "a functional bowel disorder that presents as persistently difficult, infrequent, or seemingly incomplete defecation, which does not meet Irritable Bowel Syndrome criteria."3 Irritable bowel syndrome, or IBS, is a syndrome characterized by abdominal pain or discomfort and altered bowel movements, which can include constipation, diarrhea, or both. Some propose that chronic constipation and IBS lie along a spectrum, with pain or discomfort being very prominent in IBS, but milder and rarer in chronic constipation. The Rome III diagnostic criteria for functional constipation, which are meant to be used in clinical research but are not practical for clinical care, are the following:3

1. Must include two or more of the following:

a. Straining during at least 25% of defecations

b. Lumpy or hard stools in at least 25% of defecations

c. Sensation of incomplete evacuation for at least 25% of defecations

d. Sensation of anorectal obstruction/blockage for at least 25% of defecations

e. Manual maneuvers to facilitate at least 25% of defecations (e.g. removal of stool with the fingers, or applying support around the anus with the hand)

f. Fewer than 3 defecations per week

2. Loose stools are rarely present without the use of laxatives

3. There are insufficient criteria for Irritable Bowel Syndrome (IBS)

* Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis

These formal definitions highlight the fact that infrequent bowel movements may be part of the group of symptoms that patients with "constipation" experience, but are not necessarily the principal feature.

"I only have two bowel movements a week. Should I worry?"

A common misconception is that a daily bowel movement is necessary for good health, and that failure to empty stool promptly can lead to "toxic" consequences for the body.5 The modern concern with the need to have a daily bowel movement has its root in the old idea of "autointoxication, " which is the belief that toxins can form when undigested food stays in the large intestine (the colon) for too long, and can then be absorbed into the body and cause all kinds of symptoms and health problems.5 There is no scientific evidence to support these ideas.

It is important to dispel fear in persons who do not achieve a daily bowel movement in order to avoid unnecessary interventions such as purges, enemas, and "cleansing" regimens. Some persons see a doctor out of concern that they have bowel movements only a few times a week, but they actually feel fine. For these patients, it is important to provide reassurance that they do not have a "medical problem." As discussed below, it is recommended that constipation be treated only when it impairs a person's quality of life.1

What causes constipation? Are there subtypes of constipation?

Constipation can be considered "primary" when no clear cause is evident, and "secondary" when there is an underlying factor or illness that can explain the constipation. Common causes of "secondary" constipation include medications (classic examples are the potent pain medications of the narcotic class, including the opioids codeine and morphine, but many other medications can also cause constipation), metabolic diseases such as diabetes, neurologic diseases such as Parkinson's disease, and pregnancy. It is recommended that opioid medications be prescribed with a bowel regimen including stool softeners or laxatives in order to prevent constipation.

What causes "primary" constipation? When patients with constipation are studied with specialized physiologic tests, some patients demonstrate specific findings.6, 7 A subgroup of patients has very slow passage, or transit, of stool through the colon (slow-transit constipation). In some of these patients, the nerves of the colon may be abnormal. Another subgroup has difficulty actually pushing out the stool from the rectum (defecatory disorders, which are referred to by numerous names including obstructed defecation, pelvic floor dysfunction, pelvic floor dyssynergia, anismus, and spastic pelvic floor). In these patients, there may be abnormalities in the muscle and nerve function of the rectum, anus, and the complex set of muscles in the floor of the pelvis, all of which must act in coordination to expel stool. A small minority has both slow transit and a defecatory disorder.

A significant fraction of persons with constipation has normal passage time through the colon and no obvious abnormality in the nerve and muscle function needed to expel stool from the rectum (normal-transit constipation). In these patients, constipation is probably explained by the perceived difficulty in achieving a bowel movement or by the presence of hard stools.2

Normal function of the colon, rectum and anus, and abnormalities in constipation

Understanding the normal function of the colon, rectum, and anus6 allows appreciation of the differences between the subgroups of primary constipation.

The right side of the colon serves to store and mix stool contents, the left side of the colon serves for storage and as a conduit of stool to the rectum, and along the length of the colon there is absorption of salts and water. Thus, the stool content in the right colon is generally looser than in the left colon. There are several patterns of normal muscle activity in the colon, including contractions that travel for long distances along the colon, contractions that don't seem to travel much, and slow and steady contractions. Powerful contractions that form a traveling wave down the colon can move stool contents for significant distances. These often occur early in the morning, and are related to the morning bowel movement that is typical for many persons. They can also occur after meals, and explain why some people feel the need to have a bowel movement after eating. During these after-meal bowel movements, it is not the meal that was just eaten that is eliminated, but rather stool that has been produced after previous meals. Persons with slow-transit constipation may demonstrate abnormalities in the motor activity of the colon, but the range of "normal" is broad, and there is no single pattern that is classic for slow-transit constipation.

The rectum is the reservoir at the end of the colon, where stool is present before it is eliminated. The anal sphincter is the ring of muscle just beyond the rectum that prevents stool from leaking out. Most of the time, pelvic muscles (the puborectalis sling) pull forward on the rectum, keeping it an angle, and the anal sphincter is contracted. Both of these conditions prevent the passage of stool. The normal process of having a bowel movement involves relaxation of the puborectalis sling, thus allowing the rectum to straighten, and relaxation of the anal sphincter. "Bearing down" increases the pressure inside the abdomen, and this can help the passage of stool when the rectum is straight and the anal sphincter is relaxed. Patients with disorders of defecation may exhibit lack of coordination of these functions. For instance, they may bear down while also contracting (instead of relaxing) the puborectalis sling and the anal sphincter. This amounts to "pushing against a closed outlet."

How common is constipation?

It is estimated that in North America, 12% to 19% of people have constipation, and that over 60 million people meet Rome criteria for the diagnosis of constipation.8 Taking all available studies, the estimates reported for the fraction of the population with constipation ranges from 2% to 27%. These studies have used different definitions of constipation and different ways of estimating how common constipation is, which likely explains the wide range in the estimates. Most patients who report constipation still have the condition one year later.

Research studies have identified subpopulations that are more likely to experience constipation.8 Women are twice as likely as men to have constipation. Non-white persons seem to have a higher rate of constipation. The elderly are more likely than younger persons to suffer from constipation. Constipation is more commonly reported by persons with lower socioeconomic status.

What routine medical tests should be done in patients with constipation?

There are few research studies that address the usefulness of specific tests in the evaluation of patients with constipation.9 The current consensus is that there is no evidence to support the routine use of blood tests, x-ray studies, or endoscopy (sigmoidoscopy or colonoscopy) in persons with constipation.1, 9

In persons who are age 50 years and older, it is reasonable to offer screening for colorectal cancer, as is recommended for all persons, even those without symptoms.1 The available evidence suggests that persons with chronic constipation who undergo sigmoidoscopy or colonoscopy (exams of the end portion of the colon or the entire colon with a flexible tube with a camera at the tip) are likely to have colon cancer and polyps (growths that could turn into cancer) at the same rate as persons without symptoms.10

Specialized tests may be useful in persons who have constipation that is difficult to treat. This is particularly the case when it comes to identifying those persons with extremely slow colonic transit, or defecation disorders, because different specific therapies may be offered to these subgroups of patients.

How should the constipated patient be approached in primary care practice?

Current expert opinion holds that in younger patients with chronic constipation and no "alarm signs" or clinical features to suggest a specific underlying disease, no medical testing is necessary.1, 3, 4 "Alarm signs" may indicate more serious underlying disease, and it is recommended that testing be performed in patients with these signs, which include bleeding from the rectum, weight loss of 10 pounds or more, family history of colon cancer or inflammatory bowel disease (ulcerative colitis or Crohn's disease), anemia (low blood count), positive fecal occult blood test (hidden blood in the stool), as well as the acute onset of symptoms in elderly persons.1, 4 Physicians should determine whether individual patients should have blood tests (e.g., to establish if high calcium or low thyroid hormone levels could be causing constipation), or other tests including sigmoidoscopy or colonoscopy. Persons who are candidates for colon cancer screening, including those who are age 50 years and older, should be offered screening.1

Treatment of constipation should be based on the severity of symptoms and their impact on a patient's quality of life.1 First, it must be determined whether the patient is bothered by the "constipation" or only by the idea of "being constipated." Patients may be reassured that achieving a bowel movement every several days is in the range of normal, and that having infrequent bowel movements is not harmful in and of itself. Those with troubling bowel symptoms should be offered treatment for their constipation.

It is a popular belief that people with constipation do not have enough fiber in their diet, do not drink enough water, and do not exercise enough.5 Although there is not much research in the area, it seems that fiber intake may not be very different in those with constipation compared to those without. However, some persons with constipation can improve with fiber supplements, as discussed below. Drinking more water would not be expected to affect the hardness of stool, because the small intestine has a very high capacity to absorb water, and in fact there is no evidence that drinking more fluid can treat constipation. Some patients report that exercise regularizes their bowel movements, although there are no good studies that support this as a treatment for constipation. Regardless, it is good general advice for people to engage in regular exercise.

For many persons with regular bowel movements, part of their "regularity" seems to be a behavior pattern that takes advantage of the times when the colon is normally active, such as in the morning and after meals. Patients with constipation should be advised to listen to their body and go to the bathroom when they feel the urge to have a bowel movement, particularly upon awakening and after eating. They should not spend excessive time in the bathroom straining, however.

What medical treatments are available for constipation?

The available medical therapies for constipation include bulking agents, stool softeners, laxatives, enemas, and prescription drugs. Many of the traditional treatments, including fiber supplements and some laxatives and stimulants, have not been studied in rigorous clinical trials.11 Although there is insufficient evidence to make formal recommendations for these treatments in practice guidelines, 1 some patients do benefit from these traditional therapies, and it is reasonable to try these before prescription medications are considered.

Stool bulking agents can bind water and thus may increase the solid as well as the water content of stool. The bulking agents include psyllium products (e.g. Metamucil, Konsyl, Perdiem, and multiple supplements), calcium polycarbophil (e.g. Fibercon), methylcellulose (e.g. Citrucel), wheat dextrin (e.g. Benefiber), and bran. Available evidence suggests that psyllium increases stool frequency, but there is insufficient evidence to make firm recommendations about other bulking agents.1 In clinical practice and in the over-the-counter setting, bulking agents can help some persons with constipation. Bulking agents make some patients feel worse. Bloating, for instance, may worsen. In these persons, the agents should be stopped. There is no reason to increase the dose of these treatments to high levels in those who do not benefit from standard doses.5

There is limited evidence on stool softeners such as docusate sodium (e.g., Colace) or docusate calcium (e.g., Surfak) and some of the results of clinical trials are conflicting. These agents are like detergents that allow water to mix better with stool. Stool softeners may have some, possibly minimal, benefit in constipation.1

There are two major types of laxatives. Osmotic laxatives are substances that tend to stay inside the intestines instead of being absorbed into the body. When these substances stay in the intestines, they retain fluid, and they can promote the transit of stool as well as make the stool softer or even loose. Stimulant laxatives are believed to activate nerves that control the muscle function of the colon as well as affect absorption of salts and water, thereby promoting stool transit and lessening the hardness of stool. Overuse of laxatives can lead to diarrhea and significant imbalances in the levels of salts in the blood, so caution must be exercised when using these therapies.

Polyethylene glycol (e.g., MiraLax, GlycoLax) is a well-studied osmotic laxative. Until recently, this medication was available in the United States only by prescription, but it is now available over the counter. Several studies have assessed the benefit of polyethylene glycol in constipation.1 Polyethylene glycol has been shown to increase stool frequency and improve stool consistency. Some patients experience bloating, cramping, and nausea with this medication.

Lactulose (e.g., Kristalose, Chronulac), another osmotic laxative, is a sugar that cannot be processed by humans, and passes undigested into the colon. Lactulose also improves stool frequency and consistency.1 Colonic bacteria are able to digest lactulose, and this can produce gas and bloating. Sorbitol is a similar agent that is poorly absorbed and can be fermented by bacteria in the colon.

Other osmoti

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