Snapshot A neonate is born without any complications to a 24-year-old mother who received no prenatal care or screening. At 2 days of life, the male newborn becomes irritable and inconsolable. He is noted to have abdominal distension. On review of his medical chart, his physician realizes that he failed to pass any meconium since being born. An abdominal radiograph reveals no perforation. A follow-up barium enema shows microcolon and terminal ileum with meconium. Introduction Intestinal obstruction caused by meconium in bowel lumen Classically associated with cystic fibrosis (CF) Pathogenesis secretion of hyperviscous mucus by intestinal glands thick mucus in bowel lumen causes obstruction narrowing of distal small intestine and colon Associated conditions earliest manifestation of cystic CF up to 20% of patients with CF Risk factors family history of CF or meconium ileus Presentation Symptoms failure to pass meconium rectally bilious vomiting Physical exam abdominal distension palpable bowel loops Evaluation Abdominal radiograph dilated small intestinal loops proximal to obstruction narrowed loops distal to obstruction Contrast enema with water-soluble contrast (Gastrografin, barium, etc.) diagnosis and treatment most definitive diagnosis microcolon from non-use Sweat test after 48 hours of age for CF diagnosis Differential Diagnosis Intestinal atresia Hirschsprung disease Volvulus Treatment Water-soluble contrast enema in simple cases Surgery in complicated cases or those that fail the enema Supportive care Oral gastric tube Prognosis, Prevention, and Complications Prognosis low risk of mortality with treatment likely to develop other conditions in life bowel obstructions Complications intussusception segmental volvulus meconium peritonitis