Neonatal bowel obstruction (NBO) or neonatal intestinal obstruction is the most common surgical emergency in the

neonatal period An infant or baby is the very young offspring of human beings. ''Infant'' (from the Latin word ''infans'', meaning 'unable to speak' or 'speechless') is a formal or specialised synonym for the common term ''baby''. The terms may also be used t ...

. It may occur due to a variety of conditions and has an excellent outcome based on timely

diagnosis Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...

and appropriate intervention.

Presentation

The neonatal

bowel obstruction Bowel obstruction, also known as intestinal obstruction, is a mechanical or Ileus, functional obstruction of the Gastrointestinal tract#Lower gastrointestinal tract, intestines which prevents the normal movement of the products of digestion. Eith ...

is suspected based on

polyhydramnios Polyhydramnios is a medical condition describing an excess of amniotic fluid in the amniotic sac. It is seen in about 1% of pregnancies. It is typically diagnosed when the amniotic fluid index (AFI) is greater than 24 cm. There are two clin ...

in utero,

bilious Bile (from Latin ''bilis''), or gall, is a dark-green-to-yellowish-brown fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver (liver bile) ...

vomiting, failure to pass

meconium Meconium is the earliest stool of a mammalian infant resulting from defecation. Unlike later feces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, amniotic ...

in the first day of life, and abdominal distension. The presentations of NBO may vary. It may be subtle and easily overlooked on

physical examination In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions about the patien ...

or can involve massive abdominal distension,

respiratory distress Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing disc ...

and

cardiovascular collapse Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thi ...

. Unlike older children, neonates with unrecognized intestinal obstruction deteriorate rapidly.

Diagnosis

Neonatal bowel obstruction is grouped into two general categories: high, or proximal, obstruction and low, or distal obstruction, both of which are suspected by failure to pass

at birth. High obstruction can be suspected based on the double bubble sign. Cases without distal gas are usually related to duodenal atresia, while high obstruction with distal gas need an upper gastrointestinal series because of the need to distinguish duodenal web, duodenal stenosis and

annular pancreas Annular pancreas is a rare condition in which the second part of the duodenum is surrounded by a ring of pancreatic tissue continuous with the head of the pancreas. This portion of the pancreas can constrict the duodenum and block or impair the fl ...

from

midgut volvulus A volvulus is when a loop of intestine twists around itself and the mesentery that supports it, resulting in a bowel obstruction. Symptoms include abdominal pain, abdominal bloating, vomiting, constipation, and bloody stool. Onset of symptoms ma ...

, the latter being a

surgical emergency Surgical emergency is a medical emergency for which immediate surgical intervention is the only way to solve the problem successfully. The following conditions are surgical emergencies: * Acute trauma Cardiothoracic * Cardiac tamponade * Acute ...

. Confirmation is ultimately by surgical intervention. A low obstruction is suspected on plain film, but needs follow up with a

gastrografin Diatrizoate, also known as amidotrizoate, is a contrast agent used during X-ray imaging. This includes visualizing veins, the urinary system, spleen, and joints, as well as computer tomography (CT scan). It is given by mouth, injection into a vei ...

enema, which itself can be therapeutic. The differential for low obstruction is

ileal atresia The ileum () is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine ma ...

meconium ileus Meconium is the earliest stool of a mammalian infant resulting from defecation. Unlike later feces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, amniotic ...

meconium plug syndrome Meconium is the earliest stool of a mammalian infant resulting from defecation. Unlike later feces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, amniotic ...

and

Hirschsprung disease Hirschsprung's disease (HD or HSCR) is a birth defect in which nerves are missing from parts of the intestine. The most prominent symptom is constipation. Other symptoms may include vomiting, abdominal pain, diarrhea and slow growth. Symptoms usu ...

. In cases of meconium ileus or ileal atresia, the colon distal to the obstruction is hypoplastic, usually less than 1 cm in caliber, as development of normal colonic caliber '' in utero'' is due to the passage of meconium, which does not occur in either of these conditions. When diffusely small caliber is seen, it is referred to as microcolon. Radiographs in meconium ileus classically demonstrate a bubbly appearance in the right lower quadrant due to a combination of ingested air and meconium. If, on contrast enema, reflux into the dilated distal small bowel loops can be achieved, the study is both diagnostic and therapeutic, as the ionic contrast medium can dissolve the meconium to allow passage of enteric content into the unused colon. If contrast cannot be refluxed into the distal small bowel, ileal atresia remains a diagnostic possibility.

Treatment

Jejunal and ileal atresia are caused by ''in utero'' vascular insults, leading to poor recanalization of distal small bowel segments, a condition in which surgical resection and reanastamosis are mandatory. Hirschsprung disease is due to an arrest in neural cell

ganglia A ganglion is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system there are both sympatheti ...

, leading to absent innervation of a segment distal bowel, and appears as a massively dilated segment of distal bowel on contrast enema. Surgical resection is necessary for this condition as well.

Imperforate anus An imperforate anus or anorectal malformations (ARMs) are birth defects in which the rectum is malformed. ARMs are a spectrum of different congenital anomalies which vary from fairly minor lesions to complex anomalies. The cause of ARMs is unknow ...

also requires surgical management, with the diagnosis made by inability to pass the rectal tube through the anal sphincter. Supportive intravenous hydration, gastric decompression, and ventilatory support may be needed due to poor neonatal nutrition resulting from dysfunctional bowel absorption.

Prognosis

With early intervention, morbidity and mortality of cases of intestinal obstruction is low. The outcome is in part dependent upon congenital comorbidities and delays in diagnosis and management.

Epidemiology

It has an estimated incidence of about 1 in 2000 live births.

References

External links

{{Congenital malformations and deformations of digestive system Congenital disorders of digestive system Neonatology