Constipation in Children

Difficulties with defecation are common in infants and children. Most problems are short-lived and of little consequence. Fluid/dietary alterations often resolve the problem, although a stool softener must be prescribed on occasion. Although chronic constipation may be secondary to anatomic/pathophysiologic abnormalities in a small number of patients (Table 1), it most often follows an inadequately managed acute problem. Persistent difficulty with the passage of stool often leads to impaction, stool withholding, and, eventually, fecal soiling. Weaver and Steiner recently reported their observations on the bowel habits of 350 preschool youngsters living in and around Newcastle upon Tyne, Great Britain. These children consumed a low fiber diet typical for the area. They found that 85% of these 1-to 4-year-old children passed stool once or twice a day, and 96% did so three times daily to once every other day. They observed that most (at all ages studied) produced soft stools of about 25 mL volume. PHYSIOLOGIC STUDIES Anorectal manometric studies have been performed in normal infants and children and in children with significant constipation. Distention of the rectum of normal subjects results in reflex relaxation of the internal anal sphincter and contraction of the external anal sphincter. There appears to be a proportionate relationship between the volume of rectal distention and the amplitude of relaxation and contraction of the anal sphincteric components.