University of Virginia Health System

How do we treat chronic constipation?

There are many different ways to treat childhood constipation, but in the end, most treatments revolve around three basic principals:

1. Empty the large intestine
2. Once the large intestine has been emptied, establish regular bowel movements
3. Eliminate the pain associated with passing bowel movements

There are many different ways of accomplishing the three principals above. Early on, constipation can often be treated by changing a child's diet but once the constipation becomes chronic, laxatives are usually needed to re-establish regular bowel movements and eliminate the pain associated with passing bowel movements.

How do we empty the large intestine?

There are three commonly used methods of emptying the large intestine:

1. Administering enemas -

   When we administer an enema, we push fluid into the rectum. The fluid softens the stool in the rectum but it also stretches the rectum giving the child a tremendous urge to pass a bowel movement. Almost all enemas consist mostly of water with something else mixed in to keep the water inside the intestine. The most commonly used enemas are:

   • Fleet's® Phosphosoda enemas contain water and the salt sodium-phosphate. The phosphate is not absorbed in the lower intestine and thus keeps the water from the enema in the intestine with it.
   • Soap suds enemas contain water with a small amount of soap. The soap is mildly irritating and stimulates the lower intestine to secrete water and salt.
   • Milk and Molassas enemas contain milk sugars and proteins as well as molassas. None of these are absorbed in the lower intestine and thus keep the water from the enema in the intestine.
2. Administer suppositories -

   By administering a suppository, we irritate the bottom of the intestine, causing it to contract (squeeze) and push out a bowel movement. Some suppositories also stimulate the intestine to secrete salt and water softening the stool in the rectum and making it easier to push out. Commonly used suppositories include:

   • Glycerine
   • Dulcolax®
   • BabyLax®
3. Administer powerful laxatives to "flush out" the lower intestine -

   When we administer very powerful laxatives to "flush out" the lower intestine, we are generally keeping lots and lots of water in the intestine, softening any stool in the lower intestine, and causing diarrhea. Laxatives used to flush out the intestine include:

   • Magnesium citrate
   • Golytely® or Colyte®
   • Fleet's Phosphosoda®
   • Miralax® or Glycolax®

How can we re-establish regular bowel movements?

Once the large intestine has been emptied, laxatives are administered regularly to produce soft bowel movements once or twice each day. Virtually any laxative preparation will be effective if it is given in high enough doses. Most of the commonly employed laxatives work by keeping large amounts of water in the intestinal tract, thus making the bowel movements very soft and keeping the stool moving quickly through the large intestine. Commonly employed laxative preparations include:

• Milk of Magnesia® and Haley's M.O.® - these laxatives contain magnesium salts that are very poorly absorbed by the intestinal tract. As a result, the magnesium remains in the intestine and keeps water with it. The end result is that there is much more water in the stool, keeping it very soft, and causing it to move through the intestine more quickly. In high doses, magnesium salts often produce diarrhea.
• Lactulose (Chronulac® and Duphalax®) - these laxatives contain a sugar that is not absorbed by the intestinal tract.  As a result, the sugar (lactulose) remains in the intestine and keeps water with it.  The end result is that there is much more water in the stool, keeping it very soft, and causing it to move through the intestine more quickly.  Many people who take lactulose will experience bloating and excessive amounts of intestinal gas.  In high doses, lactulose often produces diarrhea.
• Sennokot®, Fletcher's Castoria®, Ex-Lax®, Aloe Vera- these laxatives contain the natural plant derivative senna. Senna stimulates the intestine to secrete salt and water so that there is much more water in the stool, keeping it very soft, and causing it to move through the intestine more quickly. Senna also is a mild irritant, causing the lower intestine to contract (squeeze). In some children, high doses of senna cause cramps and diarrhea.
• Polyethylene glycol 3350 (Miralax® or Glycolax®) - these laxatives contains a very large polymer of 3350 molecules of ethylene glycol.  Because the polymer is so large, it is not absorbed by the intestinal tract.  As a result, the polymer remains in the intestine and keeps water with it.  The end result is that there is much more water in the stool, keeping it soft, and causing it to move through the intestine more quickly.  One of the advantages of Miralax® and Glycolax® is that they are a tasteless and odorless powder than can be readily mixed into juices or other fluids without altering their taste.  In high doses, Miralax® and Glycolax often produce diarrhea.  
• Mineral Oil - many people believe that mineral oil works by "lubricating the intestine". Mineral oil is a non-absorbable oil that is digested by bacteria living in the large intestine. Some of the by-products of this digestion stimulate the intestine to secrete salt and water. This results in there being much more water in the stool, keeping it very soft, and causing it to move through the intestine more quickly. When taking high doses of mineral oil, many children will experience some orange seepage as well as some itching at their anus.
• Metamucil®, Citrucel®, Fibercon®, Fiberall®, and Maltsupex® - these are all fiber-based laxatives. Fiber laxatives contain complex sugars that are not digested or absorbed in the intestine. As a result, the sugars remain in the intestine and keep water with them. The end result is that there is much more water in the stool, keeping it very soft, and causing it to move through the intestine more quickly. In high doses, fiber laxatives often cause bloating and gas.

Can diet accomplish the same thing as these laxatives?

In high enough doses, many foods are very effective laxatives however it is often difficult to eat or drink enough of these foods day in and day out to be effective long-term treatments. In high doses most fruits and juices can be very effective laxatives. Many people are familiar with using prunes as laxatives. Much like fiber laxatives, prunes contain complex sugars that are not digested or absorbed in the intestine. As a result, the sugars remain in the intestine and keep water with them. The end result is that there is much more water in the stool, keeping it very soft, and causing it to move through the intestine more quickly. As with fiber laxatives, high doses of prunes often produce bloating and gas.

Are laxatives safe?

While many parents and physicians are worried about using laxatives in children, most of their concerns are unfounded. Some common misconceptions include:

• Children may become "dependent" on laxatives if they use them too long.

  Since nearly all available laxatives work by keeping large amounts of water in the stool, they can be used for very prolonged periods of time without significant risk. There is no evidence that any of the laxatives described above can result in dependency with chronic usage.

• Laxatives lose their effectiveness if they are used for prolonged periods.

  No studies have ever convincingly demonstrated that any of the laxatives described above lose their effectiveness over time.

• Children who use laxatives have an increased risk of developing colon cancer.

  While several studies have suggested that adults with untreated constipation may be at increased risk for developing colon cancer, there is no evidence to suggest that laxatives increase this risk.

How long do we need to continue treatment?

The length of treatment varies from child to child, but in general, we must treat younger children for longer periods of time than older children. 

• In children older than age five or six, three or four months of continuous laxative therapy is usually sufficient to reverse many of the problems described above.  

• In children less than five years of age, we usually recommend continuous treatment with laxatives for at least six months, and sometimes as long as a year. 

Younger children need to be treated longer than older children not because the problem is more severe, but rather, because of their developmentalstage.   Young children are "magical thinkers" . . .they don't associate cause and effect the same way older children or adults do, so we need to treat them long enough that they lose the association between passing bowel movements and pain . . . they need to forget the pain.  Toddlers are like elephants, they never forget!

How can we eliminate the pain associated with bowel movements?

The key to eliminating pain associated with bowel movements is to be sure the bowel movements are soft and not particularly large. In those children who have chronic anal fissures, it may be necessary to administer some form of medicine that is soothing and promotes the healing process.

Are there other things we can do to make treatment easier and more effective?

While almost all treatment regimens revolve around evacuating the intestine and using laxatives to keep the stools soft, a number of behavioral techniques can be quite helpful.

Children who are toilet trained should get in the habit of sitting on the toilet for five to ten minutes after breakfast and again after supper. Many families have very busy schedules and their children are not in the habit of "making time" to pass bowel movements. By establishing regular "bathroom times" after meals, we take advantage of intestinal contractions that occur after we eat. These contractions are often called the "gastro-colic reflex" and they explain why some people pass bowel movements every morning after breakfast or every evening after supper. It is also useful to establish regular bathroom times after breakfast and after supper because many children are completely unwilling to pass bowel movements at school (just as many adults are unwilling to go to pass bowel movements at work).

Some pediatric centers offer biofeedback therapy as a way of improving the muscle coordination associated with passing bowel movements. Remember, many children with chronic constipation have become quite incoordinated and use muscles against one another when they try to pass bowel movements. With biofeedback, several small wires are taped to the skin around the anus and on the abdomen. These wires can measure what the different muscle are doing and display this information on a television screen. By playing a type of video game, a child can learn how to tighten and relax his or her muscles in ways that make passing bowel movements more efficient and less painful.

In older children, we often find that in conjunction with the use of laxatives and enemas, the aid of a behavioral psychologist to enlist the child's help in his or her own cure is very worthwhile. At the Children's Medical Center we have developed a program with the assistance of behavioral psychologists that we call enhanced toilet training.  By using modeling and other behavior modification techniques, this program helps children understand how to use their muscles correctly while straining.