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Obstruction of the gastrointestinal (GI) tract can be due to a wide range of causes with many similarities in clinical presentation. Abdominal pain, early satiety or anorexia, and vomiting are common, with abdominal distention being more common with lower tract blockage. Nonbilious emesis is seen in conditions that occur proximal to the sphincter of Oddi or early in the course of abnormalities occurring more distally. Conversely, bilious emesis is seen when obstruction or dysfunction occurs distal to the duodenum.
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Obstruction can result from extrinsic compression, intrinsic blockage, or functional abnormalities leading to dysmotility, as detailed in Table 154-1. This chapter focuses on three of the more common causes of GI tract obstruction in children: pyloric stenosis, malrotation with and without volvulus, and intussusception.
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Infantile hypertrophic pyloric stenosis (IHPS) is one of the most common surgically correctable causes of vomiting in infants. The incidence is about 1 in 250 to 500 with a 4:1 male preponderance; it is seen commonly in white and Hispanic infants and is rare in African, Indian, and Asian infants.1,2 The familial incidence of pyloric stenosis is remarkable: the highest incidence of pyloric stenosis occurs in the male children of mothers who had pyloric stenosis, and there is a 15-fold increase in siblings of affected patients.3,4 Traditional teaching has been that it is more common in firstborn males. The incidence of IHPS seems to be decreasing and seasonal variation has been recognized with the most common occurrences in the summer.5
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Pyloric stenosis results from hypertrophy of the pylorus muscle with associated abnormalities in innervation and obstruction of the lumen with redundant mucosa. Although infectious causes have been speculated,6 the cause of the hypertrophy is unclear. Early exposure to erythromycin has also been considered a factor in the development of this condition.7,8
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CLINICAL PRESENTATION
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Most infants with pyloric stenosis present between the ages of 3 and 8 weeks with progressive nonbilious emesis in large quantities, often forceful (“projectile”), after every feeding. The infant usually remains eager to feed, and recognition of the condition typically occurs before the infant experiences severe dehydration. ...