Treating kid's persistent constipation

Q: How common is it to treat constipation in a child with Miralax - for more than three years? Are there other treatments? Can it be controlled by diet?

A: I have certainly seen constipation in children treated with Miralax for extended periods of time, even years.

Usually these children have chronic constipation, the kind that lasts for a long time, is difficult to treat and comes back quickly if untreated. Miralax is one of the more gentle agents to treat chronic constipation. It works by drawing water into the intestine, which helps stool stay soft and pass through the intestine more quickly.

Miralax has few side effects. It isn't absorbed into the bloodstream. It is tasteless and mixes easily with juice or milk, so children will usually not protest about taking it compared to many other medications.

Whenever a medication is used for such a long time, it should be done under careful medical supervision. In this case, if the child hasn't seen a gastroenterologist, the kind of doctor who specializes in problems of the digestive system, it might be a good idea to do so.

On rare occasions, chronic constipation can be a sign of a more serious problem, such as an underactive thyroid gland (hypothyroidism), cystic fibrosis, or abnormal nerve stimulation of the intestines (e.g. Hirschsprung's disease).

Improving the diet can make a big difference in treating constipation. A high-fiber diet is best, with lots of fruits, vegetables and whole grains. Bran cereals can help, and prunes or prune juice are natural laxatives. Drinking plenty of water and other fluids is important, too.

- Claire McCarthy, M.D., is a senior medical editor for Harvard Health Publications. She is an instructor in pediatrics at Harvard Medical School, an attending physician at Children's Hospital of Boston, Mass., and director of the pediatrics department at Martha Eliot Health Center, a neighborhood health service of Children's Hospital. Dr. McCarthy has authored two books, "Learning How the Heart Beats" and "Everyone's Children.")

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