In this post, I review, link to, and excerpt from PedsCases An Approach to Pediatric Bowel Obstruction, by Kevin.Verhoeff Jun 19, 2020: This podcast presents an approach to diagnosing and managing an important pediatric emergency, pediatric bowel obstruction. Compared to … Continue reading →

Given the large differential for bowel obstruction in children it is helpful to break it up into conditions that present in the newborn period, and other conditions that present later in infancy and childhood.

A 2-week-old girl is brought to the emergency room with acute onset bilious vomiting. Further history demonstrates that she passed meconium in the first 24 hours, was doing well with 2
normal yellow stools every day with no blood or melena, but on presentation today has not stooled in the last 24 hours. She has been febrile and is irritable with distention and peritoneal findings on exam.

In a second case, you are on your pediatrics rotation and rounding on a newborn boy with known Down syndrome. The boy’s vitals are within normal ranges but after speaking with the parents they are concerned because he has been vomiting bilious material since delivery shortly after every feed. He has also not had any bowel movements. On exam, the boy appears well, but has not tolerated any oral intake since birth.

Neonatal causes for bowel obstruction occur primarily due to congenital processes. The most common embryological defect is malrotation.

The first case represents malrotation and volvulus,and is one of the pediatric presentations that may have “RED FLAG” symptoms requiring immediate attention. Any patient presenting with new onset BILIOUS emesis, marked abdominal distension, associated with a fever, elevated white blood cell count, and physical signs of localized and/or generalized peritoneal findings should be considered a surgical emergency. These findings signify an acute abdomen. A stable patient with these symptoms may be investigated with an urgent upper GI contrast study to exclude malrotation with volvulus, even in the middle of the night. An unstable patient such as the one in our case may better served with an urgent laparotomy.

Other congenital issues and causes for neonatal bowel obstruction exist as well.

Your differential for neonates should also include meconium ileus (which is often the first clinical sign of cystic fibrosis), Hirschsprung disease, abdominal wall defects (including gastroschisis and omphalocele), and imperforate anus. Finally, incarcerated inguinal hernia is a common and often overlooked cause of bowel obstruction in the premature population. To learn more, there are great PedsCases podcasts on both Hirschsprung Disease and Pediatric Hernias.

Infancy and Childhood Differential Diagnoses:

After approximately the first 4-weeks of life up to 2 years of age your differential should shift to consider other causes of bowel obstruction. Consider the following 2 clinical cases:

You are seeing a 6-week-old first born male in a pediatrician’s clinic who appears unwell. His father tells you that for the last 2 weeks he has had more frequent episodes of non-bilious, projectile emesis that occurs after being breast fed. The dad tells you that recently, he has projectile vomiting after each feed, that he is lethargic, has been having fewer stools with no
bowel movements in the last 2 days, appears to be losing weight, and has fewer wet diapers.
On exam, you recognize a 6-week old child with sunken eyes and delayed capillary refill. Abdominal exam is benign with no distention, no pain, and a scaphoid abdomen.

In the second case, a 15-year-old male with a history of neurodevelopmental delays, G-tube feeds and a fundoplication presents with abdominal pain, bilious vomiting, and obstipation. He is not tolerating any feeds without vomiting. On exam, you note surgical scars on the abdomen, with significant distention, and tenderness to light percussion.

The differential diagnosis during infancy and childhood should include things such as intussusception, pyloric stenosis, annular pancreas, necrotizing enterocolitis associated adhesions, surgical adhesions, neoplasm, and cystic fibrosis. Of course, don’t overlook the possibility of functional constipation in these patients. To learn more, there are great PedsCases podcasts on intussusception, and necrotizing enterocolitis.

Of note, another diagnosis that should always be part of any differential diagnosis for acute abdominal symptoms is appendicitis. Appendicitis is known to be a great mimicker of multiple pathologies. A perforated appendix and abscess can cause a non-mechanical bowel obstruction. Young children may present with a several days’ history of vague abdominal
symptoms, fever, obstruction and emesis.

In the first case we discussed, the infant has had progressive worsening of symptoms, nonbilious but projectile vomiting after feeds, and appears quite unwell. There is no mention of
abdominal distention, pain, or peritoneal signs and the progressive nature and other signs would suggest pyloric stenosis as the diagnosis. Symptoms were not immediate at birth,and worsened as the pylorus became tighter as it hypertrophied. The vomit in pyloric stenosis is not bilious
because the obstruction is in the pylorus of the stomach, proximal to where bile is released into the GI tract. In these cases, you may also note an “olive pit” like mass in the patient’s
epigastrium and commonly find hypochloremic, hypokalemic, metabolic alkalosis on the bloodwork. Abdominal ultrasound is the gold standard imaging modality and can demonstrate a
ultrasound is non-diagnostic and would show lack of contrast flow past the stomach.

In the second case, a complex male with a history of abdominal surgery presented with classic signs of a bowel obstruction due to adhesions. This is important to consider in any patient with a
history of prior abdominal surgery. An abdominal X-ray showed dilated loops of bowel with multiple air-fluid levels, supporting the diagnosis.

Links To And Excerpts From “Information for Pediatric Healthcare Providers” On COVID-19 From The CDC