WHY CONSTIPATION?

To understand why people with neuromuscular disorders are prone to constipation, which can be debilitating and even disabling, you have to understand a little about how the gastrointestinal tract - or gut - works. The gut is actually a long, hollow tube that goes from the mouth to the anus. It's open at both ends so that food can go in and waste products can be moved out. What most people don't know is that the gut is a very important organ in terms of absorption of nutrients from the food we eat and the balance of water and charged particles called ions in our bodies.

The walls of the gut - the esophagus (tube from the mouth to the stomach), the stomach wall, the walls of the small and large intestines, and the rectum - allow water and ions to move across them and be absorbed by the blood.

Most of this nutrient absorption from the intestines into the bloodstream takes place in the small intestine. From there, watery sludge is moved into the large intestine, also called the colon, where more water (but few nutrients) are absorbed across the gut wall, resulting in fecal material that's formed and usually not too watery.

The longer this material stays in the colon, the more water is absorbed across the gut wall, and the harder and drier the feces become - in other words, constipation results.

CONSTIPATION AND NEUROMUSCULAR DISEASE

The actual functioning of the gut from mouth to anus is almost entirely under the control of the autonomic nervous system, that part of the nervous system that controls automatic functions like those of our internal organs.

But, when it comes time to evacuate fecal material from the rectum - defecation - voluntary muscles come into play. We use our abdominal and thoracic (chest area) muscles to push the fecal material from the rectum. Without these muscles, it's very hard to have a bowel movement. If these muscles are impaired, as they are in most people with neuromuscular disorders at some point in their disease, bowel movements will be more difficult and less effective, setting up the person for constipation.

In the gut, food moves from the esophagus to the stomach, where it's broken down, to the small intestine, where most of the absorption of nutrients takes place, to the large intestine (colon), where water moves from the gut to the blood. Involuntary muscle action keeps things moving through the gut, but voluntary muscle action is necessary to evacuate feces effectively from the last part of the gut (rectum).

Most of the neuromuscular disorders in MDA's program - with the notable exception of myotonic muscular dystrophy (MMD) - don't involve the gut itself to any great extent. The action of the intestines, under the control of the autonomic nervous system, is through involuntary muscles in the intestinal wall. In most neuromuscular disorders, the skeletal muscles and heart are much more affected.

In myotonic dystrophy, both voluntary and involuntary muscles can be affected, making constipation and other gastrointestinal problems a major part of the disease for many people.

Whatever the neuromuscular disease, impaired mobility, lack of access to and privacy in the bathroom, and the real or perceived inconvenience of taking in adequate amounts of fluid by mouth, are frequent problems, all of which add to the risk of constipation.

THE BASICS OF MAINTENANCE
THREE P'S AND TWO F'S

First - the basics: The three P's of privacy, position and peristalsis, and the two F's for fiber and fluids can go a long way toward understanding and minimizing the effects of weak abdominal and chest muscles on the functions of the gut.

Privacy.
No one likes help in the bathroom. Even children care about privacy by the time they're in elementary school.

If you need help with toileting, try to set up a routine with your caregiver so that you have an adequate amount of time alone in the bathroom or on a portable commode - say at least 15 minutes - without being disturbed. Set up a time for the caregiver to return or set up a signaling system.

Better still, if you can afford it, purchase whatever aids there are to help you gain independence in the bathroom. Several devices are on the market that allow people to get on and off the toilet or clean up without help.

Position.
If you've ever watched a toddler in diapers having a bowel movement, you know what position they usually assume - squatting. That's the position that was assumed by most humans all over the world until recently and is still used in some areas.

In the developed countries of the West, we're not good squatters because we're trained from earliest childhood to sit on chairs, couches and toilets. But, squatting is by far the best position for certain things, like childbirth (another lost art) and defecation.

A squatting position opens the muscles of the pelvic area, angles the rectum for the best possible mechanical advantage, braces the muscles of the abdomen, and pushes the thighs into the abdomen to supply extra force for the abdominal musculature.

Even people without a disability have trouble assuming a full squatting position, but there are ways to come close and give yourself a much better mechanical advantage than the usual chairlike position most people use on the toilet.

You can approximate a squat by having your feet rest on a stool or other prop (for example, a rung of a walker) that's about a foot off the ground and then leaning forward. Holding a pillow in front of you can add leverage and apply pressure to weak abdominal muscles.

The worst position is sitting up with your feet off the ground. Unfortunately, some raised toilet seats, designed for easy mounting, cause people to take this position. Use a footstool with these.

Even those with advanced overall weakness can benefit from taking a better position for defecation. A mechanical, sling-type lift can be positioned over the toilet or commode in such a way that the buttocks are the lowest part of the body. Having a bowel movement this way takes about one-tenth the amount of time required to have a bowel movement lying down using a bedpan, say those who've tried it both ways.

Peristalsis.
This, which comes from a Greek word meaning "to wrap around," is the movement of food and what will later become feces along the gut by contractions of the involuntary muscles in the intestinal wall. These muscles are arranged in both a circular and lengthwise pattern all along the gut.

Peristalsis in the colon usually occurs between 20 and 45 minutes after a meal (you can see which pattern fits you best) and is usually strongest after breakfast. Timing your bowel routine to this peristaltic reflex puts nature on your side in overcoming any muscle weakness you may have.

If an after-breakfast bowel routine isn't convenient, you can usually train your body to observe an after-lunch or after-dinner time for defecation. Allow at least 10 to 15 minutes for the bowels to move. If constipation has been a problem, the colon may have become distended and lost muscle tone. In these cases, it can take as long as four to six weeks to re-establish a normal pattern of evacuation. Be patient.

Fiber and fluids.
Fiber and fluids are the mainstay of dietary prevention and treatment of constipation. But beware: They have to go together.

Some types of fiber, such as bran (like that found in bran cereals) and over-the-counter fiber preparations (the Metamucil type) can take on the consistency of hardened cement if they're taken without adequate water or watery liquids like juice. Commercial fiber products carry warning labels telling the consumer that taking them without water can even lead to blockages of the throat or esophagus.

So, what is fiber, anyway? Fiber - which used to be more commonly called "roughage" - is the part of food that we can take in but can't digest. The skins and husks of fruits and vegetables, parts of the seeds or bark of many plants, and much of the content of lettuce and celery are fiber.

The main reason these substances relieve or prevent constipation is that they can't be digested and therefore stay in the colon, where they absorb water like a sponge. When water stays in the colon, the feces become softer and wetter, which makes them easier to pass. Fiber also swells up in water, causing an increase in fecal bulk. This increase stimulates peristalsis in the colon.

There's fiber, and then there's fiber. The fiber in fruits such as apples, strawberries, watermelon and pineapples, and vegetables such as cucumbers with the skin on, lettuce and celery, can be at least partially broken down and has a "milder" effect on the gut. You may want to start with this type of fiber if you're not sure how you'll respond.

The fiber in bran and other seed preparations is completely indigestible and can markedly increase stool bulk, fluid content and peristalsis. If you don't take it with enough water, it can cause obstruction. In some people, especially where muscle weakness is severe, the stools can become too bulky to pass. So go easy on this type of fiber; increase it gradually.

BEYOND BASICS - MEDICATIONS FOR MAINTENANCE

There are certainly some people with neuromuscular disorders who can manage their gut problems with the interventions above most or all of the time. But, for others, more may be needed.

Health advice in the media often warns people against "laxative abuse," and this is probably good advice for the average person who doesn't have any muscle or neurologic problems but who's convinced he needs to have a bowel movement every day.

If you keep taking a laxative to make that happen, the intestines can become insensitive to the normal defecation signals until a laxative becomes necessary to produce any action at all - a kind of addiction process.

However, in neuromuscular disease, the threat of laxative addiction has to be balanced with the need to produce regular bowel movements despite the presence of often severe and progressive muscle weakness. The idea is to start with the simplest and best-tolerated medications, if any are needed, and go on from there as necessary.

The first step, if the three P's and two F's aren't adequate, is usually to add some sort of medication to the bowel regimen. Often, this is a bulk-forming laxative. Bulk-forming laxatives are made of fiber, so they're really just a way of taking in dietary fiber in a concentrated form.

Examples are methylcellulose (like Citrucel) and psyllium seeds (Meta-mucil is one brand). These come in granules that have to be dissolved and taken with at least 8 ounces of water or juice. Metamucil also comes in convenient wafers (cookies), but these also have to be taken with adequate liquid.

After the usual bulk-forming laxatives, there are a great variety of over-the-counter laxative products to choose from. Some people find they have to alternate among an arsenal of products, as the body seems to get used to a product and become functionally "immune" to its action. Please consult your health-care professional - doctor, nurse specialist or dietitian - for advice on your particular situation.

Despite advertising claims, the line between "harsh stimulants," "gentle softeners" and products that "work with your body to give you gentle, overnight relief" isn't really all that clear. The extent to which a laxative is "harsh" (meaning producing an immediate bowel movement that may be accompanied by cramping or watery stools) as opposed to "gentle" (causing a formed stool within a day or so) can depend on the dose.

And even though many manufacturers tout their products as being "natural" compared with those of other companies, in reality, most laxatives are derived from natural plant materials or from oils, salts or sugars. These are natural whether they're purchased in a health-food store or a discount drug outlet.

If the more common bulk-forming fiber products aren't working, the next step is usually to add or substitute another oral laxative. Some of the choices are mineral oil products (Neo-Cultol); magnesium hydroxide (Phillips' Milk of Magnesia); a sugar product called lactulose (Cepulac); plant-derived senna products (such as Senokot syrup or tablets); barley malt products, which is a slightly different kind of bulking agent (Maltsupex); docusate sodium (Colace); or combination products (like Haley's M-O, which contains mineral oil and magnesium hydroxide).

Mineral oil is just what it sounds like - a mixture of hydrocarbons not too different from an industrial lubricant. It can be used orally or as an enema and simply lubricates the stool for easier passage. It can't be taken for a long time, because it interferes with the absorption of some of the vitamins. Care has to be taken not to inhale the oil droplets into the lungs.

Magnesium hydroxide and related salts made with sodium or potassium are known as osmotic laxatives, in that they stay in the gut and draw in water, a process called osmosis.

Lactulose is a complex and poorly absorbed sugar, which sits in the intestine and is metabolized into lactic, formic and acetic acids. These acids have an osmotic effect.

Senna products come from the pods of senna plants. They increase water content in the bowel, probably because of their fiber content, and also directly increase intestinal motility (peristalsis). Because of this latter effect, they belong to a group of medications known as stimulant laxatives.

Barley malt is a grain that's been soaked and allowed to sprout. It has a high fiber content and is a bulk-forming laxative. Its action may be slightly different from that of other fiber products.

Docusate sodium is a surfactant laxative, also known as a wetting agent. It allows more water than usual to penetrate the fecal material, making the stools easier to pass. It has to be taken with a full glass of water.

These can be combined, alternated or mixed in one preparation, such as Haley's M-O.

Rectal medications, such as enemas and suppositories (see below), can also be used to maintain bowel function, but with caution and medical advice.

MEDICATIONS FOR 'CLEANOUT'

Most people aren't good at squatting, but you can get closer to the proper position by using a footstool and leaning forward on the toilet. A pillow can also help brace abdominal muscles.

The above products - actually only a sampling of what's out there - are used in low or moderate doses to prevent acute constipation, but what if you're already acutely constipated?

This condition is called fecal impaction. It's particularly common in children with neuromuscular conditions, but it can certainly occur in adults as well. What happens is that defecation is delayed for more than a few days, allowing more and more water to be absorbed from the lower colon and more and more fecal material to accumulate. The result: a huge fecal mass that can't be pushed out, especially when there's significant muscle weakness.

Adults usually know when there's an impaction by the feeling of unpleasant fullness in the rectum. Children may not recognize this feeling, but the mass can be felt by inserting a gloved finger into the rectum. The problem can be especially severe in children, because, fearing pain, they may "hold onto" feces even longer than adults will, not realizing that they're only making the problem worse. (Sometimes, watery fecal material leaks around the impacted mass, causing the parents to think that there's no problem or that the child has diarrhea - another factor in worsening the situation.)

Fecal impaction usually calls for some fairly drastic measures to clean out the rectum. In some cases, the bulk of the impaction may have to be manually removed by a doctor or nurse. Then, enemas, suppositories or high-dose mineral oil can be used to empty the distended rectum and lower colon and help the bowel contract back down to a normal size, after which a maintenance plan can be started or resumed.

The following are available over the counter, but, like other products, should be used in consultation with your health-care professional.

Packaged enemas, such as Fleet brand, come in a variety of formulations. The usual kind contain salts similar to those found in oral preparations. Fleet also makes an enema with mineral oil. Enemas may be needed for several days to a week.

A new product called Therevac is known as a "mini-enema." It contains a very small amount - about one-seventh of an ounce - of a mixture of a soapy material with a lubricant (glycerin) and a wetting agent (docusate sodium). It's also available with an anesthetic agent (benzocaine) to help alleviate the pain of passing hard stools.

This kind of product may be useful in either the maintenance phase or the cleanout, depending on how serious the impaction is.

Suppositories are semisolid substances with a soapy or gelatinous base. They're usually shaped somewhat like a bullet and designed to be inserted into the rectum, where they dissolve. Popular suppositories for constipation are those made with glycerin, which softens and lubricates the stool, and those made with bisacodyl, a stimulant laxative. Small impactions may be relieved by a suppository.

An oral alternative for getting rid of an impaction is high-dose mineral oil for a few days, under medical supervision.

SPECIAL SITUATIONS

Swallowing problems.
It's easy to say that fluids and fiber are the mainstays of bowel management, but what if you can't swallow easily?

Many people with swallowing difficulties have trouble with thin liquids that have a high water content - the very kind that can best alleviate constipation. These liquids can, however, be thickened with commercial thickening products (such as Thick-It and Thick & Easy), or you can purchase pre-thickened juices (such as Lyons ReadyCare). The water content stays the same, even though the liquid is thicker.

Ask your pharmacist or dietitian for details on these products (some of which aren't sold directly to consumers), and check with your health-care provider about which one is right for you.

Of course, you can also take in foods with a high water content that are thick enough to be easily swallowed, such as ice cream, ices, puddings, yogurt, and soup thickened with potato flakes. A blender can alter the consistency of a fluid, so that you can, for example, make a tasty, high-fiber slush out of strawberries and water.

Some people have more trouble swallowing the fibrous foods themselves than they do the water, so here again food consistency has to be modified. For instance, using a blender to make bean soup easier to eat preserves the fiber content of the beans while smoothing out the texture. Bran cereal can be softened in milk before it's eaten.

Pre-packaged juices with extra fiber are available, but they're not sold directly to consumers. Lyons Ready-Care Fiber is a line of such juices.

If you're using a commercially prepared liquid formula for all or most of your nutrition, you can get constipated unless you have adequate water and/or juice with the formula. Many professionals recommend using a high-fiber version of these liquid nutritional products as well. (Jevity and Nutren with Fiber are examples.) Your pharmacist or dietitian will probably know the details about these products and how to get them for you, but your doctor can advise you on how and whether to use them.

Feeding tubes.
If you have a feeding tube that goes directly into your stomach, you're probably already experienced with both commercial liquid nutritional products and homemade, blenderized food. All the same dietary principles regarding management of constipation apply equally to food taken in through a feeding tube.

Water, prune juice, high-fiber liquid nutrition products, high-fiber juices and blenderized, liquefied fruits and vegetables can all be taken in through the tube. Things have to be blended very well so as not to clog the tube.

Consult a dietitian, pharmacist and your physician for details that apply to your particular problem. Some medications may not be advisable for people with feeding tubes.

Drug side effects.
Some medications cause constipation as a side effect. The so-called tricyclic family of antidepressants, such as amitriptyline (Elavil), clomipramine (Anafranil) and imipramine (Tofranil) are notorious for this.

Talk to your doctor about switching to another type of antidepressant, such as those in the group known as selective serotonin reuptake inhibitors (SSRIs). These include fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft) and others, and they aren't known to cause constipation.

Kids.
Getting children to cooperate with a bowel program can be a challenge. Children, like adults, are sensitive about their bowel function. They may be self-conscious about using the bathroom for bowel movements at school, especially if they need extra time or special help. Sometimes this problem can be circumvented by setting up a bowel routine that's centered around the morning and/or evening hours and doesn't overlap with the school day.

Like adults, children should be allowed as much privacy as possible in the bathroom. High-tech devices can sometimes help a child use the toilet without help.

Children often respond surprisingly well to a reward system. Kids can be rewarded for following dietary or medication measures - such as eating high-fiber cookies with a full glass of water or juice - and for sitting on the toilet for 10 to 15 minutes at the appropriate time interval following a meal (regardless of the result).

Some children will work for simple things like stickers or a promised treat. Older and wiser kids may work for plastic poker chips that can later be cashed in for desirable rewards.

Try not to get too upset about a child's bowel movements or too focused on them, but make bowel function part of the overall approach to maximizing a child's function in spite of his disability.

You can explain to a school-age child with a disorder like Duchenne or limb-girdle muscular dystrophy or spinal muscular atrophy that there's nothing wrong with his bowels or private parts but that the muscles in his belly aren't as strong as they might be and that this is the reason he has to take special precautions.

Consultants for this article were John Bach, co-director of the MDA clinic at University Hospital, Newark, N.J.; Ginna Gonzalez, certified gastroenterology registered nurse associated with the Kessenich MDA/ALS Center, Miami; June Halper, adult nurse practitioner, Teaneck, N.J.; Nancy Holland, clinical nurse specialist, New York; Christine Laforestrie, registered dietitian, Silvercrest Extended Care Facility, Jamaica, N.Y.; Jude Trautlein, registered dietitian, Children's Clinic for Rehabilitative Services, Tucson, Ariz.; and Julee Waldrop, pediatric and family nurse practitioner, Carle Clinic, Champaign, Ill.