Snapshot A 2-day-old boy is brought to the emergency department by his mother after he became inconsolable with abdominal distention and has not vomited or passed his first feces. He was born to a 27-year-old woman via spontaneous vaginal delivery without any perinatal complications. The mother was not able to attend prenatal care visits to receive appropriate screening. An abdominal radiograph is performed, which shows dilated loops of bowel without any evidence for perforation. A hyperosmotic contrast enema radiography is performed and confirms meconium ileus. A sweat test is subsequently done to work-up for cystic fibrosis. Introduction Clinical definition neonatal intestinal obstruction secondary to meconium within the lumen of the bowel that has become thickened Epidemiology Incidence can occur in approximately 20% of patients with cystic fibrosis Risk factors family history of cystic fibrosis meconium ileus low birth weight ETIOLOGY Pathogenesis accumulated thickened meconium leads to obstruction in the bowel lumen resulting in dilation of the proximal ileum wall and narrowing of the distal intestine Genetics inheritance pattern cystic fibrosis is an autosomal recessive disease mutations gene CF transmembrane conductance regulator (CFTR) gene delta F508 is the most common mutation there is a deletion of one amino acid (phenylalanine) in the 508 position of this gene protein encoded for CFTR protein Associated conditions cystic fibrosis Presentation Symptoms failure to rectally pass meconium Physical exam abdominal distension palpable bowel loops may have visible peristaltic waves Imaging Radiographs views abdominal findings dilated loops of bowel proximal to the obstruction narrowed loops of bowel distal to the obstruction may see abdominal calcifications Contrast enema indications performed to confirm and treat meconium ileus when there is no evidence of perforation views abdominal findings dilated bowel colon may appear as a microcolon Studies Labs sweat test after 48 hours of age in order to work up for cystic fibrosis Differential Diagnosis Intestinal atresia Hirschsprung disease Volvulus Treatment Non-operative hyperosmolar enema (e.g., Gastrografin) indication this is a non-operative approach to treat meconium ileus as this leads to breakdown of the thickened meconium which clears the obstruction this is typically performed in simple meconium ileus but can be used in complicated meconium ileus Operative resection with enterostomy or primary anastomosis indication can be used in cases of simple meconium ileus that does not clear with hyperosmolar enema this is typically performed in complicated meconium ileus Complications Complications intussusception segmental volvulus intestinal perforation meconium peritonitis Prognosis There is a low mortality risk after appropriate treatment of meconium ileus