[Constipation--a common problem in childhood]

Constipation in children is defined as the infrequent and difficult passage of hard stool, not necessarily associated with in-frequent stools. All healthy newborns have their first stool within the first 24 to 48 hours after birth. Intestinal transit time increases with age, therapy decreasing the frequency of stooling. ANATOMY AND PHYSIOLOGY OF ANUS AND RECTUM: Acquisition of fecal continence requires: normal internal and external anal sphincters, puborectal muscle as well as intact sensory input from both the rectal vault and anal canal. ETIOLOGY AND DIFFERENTIAL DIAGNOSIS: During the first year of life, failure to have bowel movement every other day warrants evaluation. During infancy, constipation is usually due to dietary manipulations, malnutrition or some other functional abnormalities. Anatomic causes are found only in 5% of patients.

Diagnosis relies on history and physical examination. Digital rectal examination usually reveals a shorter anal canal with decreased sphincter tone. The rectal ampulla is dilated and filled with stool. Anorectal manometry is helpful in differentiating functional constipation from aganglionosis or other neurologic problems. Treatment varies depending on the underlying cause. Bowel retraining, aimed at establishing regular daily bowel movement, is of utmost importance in children. The response to treatment is usually dramatic.

Constipation in children causes anxiety in the family and successful treatment requires persistent reassurance and repeted reevaluation.