DEFINATION   

Microcolon is a rare congenital cause of intestinal obstruction. The microcolon generally results from intrauterine underutilization of the colon, which would include conditions in which intestinal contents are not passed into the colon during gestation. This would include ileal atresia, but this would not include duodenal atresia, because duodenal atresia is in the proximal small bowel, such that the middle and distal small bowel continue to shed epithelial tissue (meconium precursors) distally into the colon during gestation. Microcolon is also part of a megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS). MMIHS is a genetic disorder with an autosomal recessive pattern of inheritance. This syndrome affects primarily female infants. Infants with MMIHS present with bilious vomiting, delayed passage of meconium and abdominal distention. Dilation of the bladder and the small bowel causes abdominal distention. Physical exam reveals thin musculature of the anterior abdominal wall. Diagnosis is confirmed by ultrasound, upper GI contrast study and an enema which shows a nonobstructed microcolon This syndrome is usually lethal within the first year of life