Constipation in Infants and Children: Evaluation and Treatment

Abstract

BACKGROUND A normal pattern of stool evacuation is thought to be a sign of health in children of all ages. Especially during the first months of life, parents pay close attention to the frequency and the characteristics of their children's defecation. Any deviation from what is thought by any family member to be normal for children may trigger a call to the nurse or a visit to the pediatrician. Thus, it is not surprising that approximately 3% of general pediatric outpatient visits and 25% of pediatric gastroenterology consultations are related to a perceived defecation disorder (1). Chronic constipation is a source of anxiety for parents who worry that a serious disease may be causing the symptom. Yet, only a small minority of children have an organic cause for constipation. Beyond the neonatal period, the most common cause of constipation is functional and has been called idiopathic constipation, functional fecal retention, and fecal withholding. In most cases the parents are worried that the child's stools are too large, too hard, painful, or too infrequent. The normal frequency of bowel movements at different ages has been defined (Table 1). Infants have a mean of four stools per day during the first week of life. This frequency gradually declines to a mean average of 1.7 stools per day at 2 years of age and 1.2 stools per day at 4 years of age (2,3). Some normal breast-fed babies do not have stools for several days or longer (4). After 4 years, the frequency of bowel movements remains unchanged.TABLE 1: Normal frequency of bowel movements Functional constipation-that is, constipation without objective evidence of a pathologic condition-most commonly is caused by painful bowel movements with resultant voluntary withholding of feces by a child who wants to avoid unpleasant defecation. Many events can lead to painful defecation such as toilet training, changes in routine or diet, stressful events, intercurrent illness, unavailability of toilets, or the child's postponing defecation because he or she is too busy. Withholding feces can lead to prolonged fecal stasis in the colon, with reabsorption of fluids and an increase in the size and consistency of the stools. The passage of large hard stools that painfully stretch the anus may frighten the child, resulting in a fearful determination to avoid all defecation. Such children respond to the urge to defecate by contracting their anal sphincter and gluteal muscles, attempting to withhold stool (5). They rise on their toes and rock back and forth while stiffening their buttocks and legs, or wriggle, fidget, or assume unusual postures, often performed while hiding in a corner. This dance-like behavior is frequently misconstrued by parents who believe that the child is straining in an attempt to defecate. Eventually, the rectum habituates to the stimulus of the enlarging fecal mass, and the urge to defecate subsides. With time, such retentive behavior becomes an automatic reaction. As the rectal wall stretches, fecal soiling may occur, angering the parents and frightening the child (6). After several days without a bowel movement, irritability, abdominal distension, cramps, and decreased oral intake may result. Although constipation is a common pediatric problem, no evidence-based guidelines for its evaluation and treatment currently exist. Therefore, the Constipation Subcommittee of the Clinical Guidelines Committee was formed by the North American Society for Pediatric Gastroenterology and Nutrition (NASPGN) to develop a clinical practice guideline. METHODS The Constipation Subcommittee, which consists of two primary care pediatricians, a clinical epidemiologist, and five pediatric gastroenterologists, addressed the problem of constipation in infants and children who had no previously established medical condition. Neonates less than 72 hours old and premature infants of less than 37 weeks' gestation were excluded from consideration. This clinical practice guideline has been designed to assist primary care pediatricians, family practitioners, nurse practitioners, physician assistants, pediatric gastroenterologists, and pediatric surgeons in the management of children with constipation in both inpatient and outpatient settings. Constipation was defined as a delay or difficulty in defecation, present for two or more weeks, and sufficient to cause significant distress to the patient. The desirable outcome of optimal management was defined as a normal stooling pattern, with interventions that have few or no adverse effects, and with resultant resumption of functional health. To develop evidence-based guidelines, articles on constipation published in English were found using Medline (7). A search for articles published from January 1966 through November 1997, revealed 3839 articles on constipation. The Cochrane Center has designed a search strategy for Medline to identify randomized controlled trials. This strategy includes controlled vocabulary and free-text terms