NeoReviews Vol.7 No.1 2006 e34
© 2006 American Academy of Pediatrics
Motility of the Colon and Anorectum
Samuel Nurko, MD, MPH*
* Center for Motility and Functional Gastrointestinal Disorders, Childrens Hospital, Boston, Mass
Abbreviations: AChE: acetylcholinesterase BM: bowel movement EAS: external anal sphincter GI: gastrointestinal HAPC: high-amplitude propagated contractions HD: Hirschsprung disease IAS: internal anal sphincter LAPC: low-amplitude propagated contractions MMIHS: megacystis microcolon intestinal hypoperistalsis syndrome NANC: nonadrenergic, noncholinergic NID: neuronal intestinal dysplasia NO: nitric oxide RAIR: rectoanal inhibitory reflex RDS: respiratory distress syndrome RMC: rectal motor complex TPN: total parenteral nutrition
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Objectives
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After completing this article, readers should be able to: - Determine how many term infants pass meconium in the first 24 hours after birth.
- Describe the timeline for passage of meconium for preterm infants.
- Explain the rectoanal inhibitory reflex and when it is present.
- Explain the method of diagnosing Hirschsprung disease.
- Name the investigation that is important in the differential diagnosis of the neonate who has symptoms of distal intestinal obstruction.
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Introduction
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Timely passage of the first stool is a hallmark of well-being in the newborn; failure to pass meconium may signal immaturity, obstruction, or a motility problem. The presence of normal colonic and anorectal motility is necessary for normal defecation. This article reviews normal bowel movement (BM) frequency in term and preterm infants, normal colonic and anorectal motility function, and common motility problems that can present in the newborn period.
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Normal Bowel Movement Frequency
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Term Infants
The time to first BM production after birth and normal BM frequency varies with age and differs between term and preterm infants (Table 1). Stools usually occur in 99% in of term infants within the first 48 hours after birth (Fig. 1). Sheryy and Kramer (2) reported that 94% of term newborns passed meconium within 24 hours of birth, with 99.8% doing so in the first 48 postnatal hours. Similar findings have been reported by others, (5) and reports on postterm infants indicate that 100% passed meconium within 24 hours. (13) Therefore, term infants who have not had a BM in the first 48 postnatal hours require further evaluation, even if they are asymptomatic. Symptomatic infants should be evaluated as soon as symptoms appear. Delayed passage of meconium in the term infant commonly is associated with Hirschsprung disease (HD), although a recent prospective study reported that only 81% of children who had HD . . . [Full Text of this Article]
Copyright © 2006 by the American Academy of Pediatrics.