Review Question - QID 109245

This patient presents with bilious vomiting, delayed passage of meconium, weight loss, dilated loops of bowel on abdominal radiograph, and microcolon on contrast enema, which is consistent with meconium ileus. Meconium ileus is strongly associated with cystic fibrosis, which in males also presents with congenital absence of the vas deferens.

Although only 10% of neonates with cystic fibrosis will present with meconium ileus, upwards of 90% of infants presenting with meconium ileus have an underlying etiology of cystic fibrosis. Patients typically present in the first three days of life with bilious vomiting and failure to pass meconium in the first 48 hours of life. Patients will have a dilated proximal bowel on abdominal radiograph with visualization of a microcolon on contrast enema. Ninety percent of males with cystic fibrosis will also have congenital absence of the vas deferens, which causes infertility later in life.

Figure A demonstrates multiple dilated loops of bowel, which is consistent with meconium ileus. Figure B demonstrates a microcolon seen on contrast enema, which is pathognomonic for meconium ileus.

Incorrect Answers:
Answer 1: Although bronchiectasis is commonly found in cystic fibrosis, it is a chronic complication that is not likely to be found in a neonate.

Answer 3: Congenital diaphragmatic hernia is commonly found in association with intestinal malrotation. Intestinal malrotation often leads to midgut volvulus in neonates, which may present with bilious vomiting. However, contrast enema would not demonstrate a microcolon in patients with malrotation.

Answer 4: Patent ductus arteriosus is commonly found in patients born prematurely, which is also associated with necrotizing enterocolitis. Necrotizing enterocolitis has a variable presentation on abdominal radiograph and may present in the early stages with dilation of the bowel, but it does not usually present so early on in life, and a microcolon would not be visualized on contrast enema.

Answer 5: A single transverse palmar crease is a sign of Down syndrome, which is also associated with Hirschsprung disease. Hirschsprung disease may present similarly to meconium ileus with bilious vomiting and delayed passage of meconium, but a transition point between dilated proximal bowel and the narrow rectosigmoid would be seen on contrast enema.

Bullet Summary:
Cystic fibrosis often presents in neonates with meconium ileus and is strongly associated (in male patients) with congenital absence of the vas deferens, which causes infertility later on in life.