It is a clinical picture that is manifested by absence of gas and stool discharge, flatulence, pain and vomiting due to obstruction of the intestinal passage due to any reason whatsoever. The condition is caused by mechanical factors, but it may also be paralytic in nature. Possible factors include hypovolemia, electrolyte losses (Na, K), intestinal infections and toxins in paralytic ileuses. Here, we deal with mechanical bowel obstructions. Although they can be seen at any age, the causative factors may vary by age ranges. While congenital anomalies are more prevalent in newborns, primary factors include invaginations, incarcerated hernias, malrotations, postoperative adhesions and obstructions caused by band formations in infants and children.
Clinical Picture: They are manifested by common symptoms that do not vary by age ranges.
- Inability to discharge gas and stool: it is manifested in newborns by inability to discharge meconium. While neonates discharge meconium within first 24 hours by 96%, it is discharged in the first 48 hours by 99.8 percent. Therefore, a mechanical obstruction should be considered in those who cannot discharge meconium in the first 2 days. The absence of gas and stool discharge in infants and children, who were otherwise healthy in the past, suggests presence of an obstructive cause.
- Abdominal distension: abdominal cavity distends as intestines are stretched by gas due to lack of the gas and stool discharge. Abdominal pain occurs as the peristalsis of the intestine is increased to overcome the obstruction.
3.Vomitting: intestinal peristalsis is gradually increased to overcome the obstruction and finally, intestinal muscles tire and the digested food cannot be moved in the lumen, resulting in rapid increase of the bacterial growth; the resultant bacterial toxins slow down and stop the peristalsis by influencing the muscular activity. When the peristalsis is reversed, the content of the stomach is first vomited.
If the obstruction persists, the content of bile in vomit is followed by vomiting fecal content. Patient dehydrates rapidly. Since aspiration of vomit leads to remarkable pulmonary problems, a nasogastric tube should definitely be inserted and the amount of fluid lost must be measured.
- Neonatal Intestinal Occlusion
- Ano-rectal malformations (imperforated anus, anal atresia, rectal atresia)
- Meconium plug syndrome
- Meconium ileus
- Hirschprung’s disease (Aganglionosis)
- Ileal and jejunal atresia- stenosis
- Duodenal atresia and stenosis
- Annular pancreas
- Preduodenal portal vein
- Stenosis of pylorus, antral web and stenosis
- Gastric volvulus
- Hiatal hernia
- Diaphragmatic hernia
- Malrotation and volvulus due to congenital peritoneal bands
- Herniation and incarceration through the mesenteric defect
- Volvulus due to residue of Meckel’s diverticulum
- Enteric cysts
- Intestinal occlusions in infants and children
- Malrotation and volvulus due to peritoneal bands
- Mesenteric hernias
- Meckel’s diverticulum volvulus and invaginations
- Obstructions secondary to postoperative adhesions and peritoneal bands
- Enteric cysts
- Enteric duplications
- Ileal obstruction due to ascaris lumbricoide
- Gastric outlet obstruction due to trichobezoars
- Gastric volvulus
- Hiatal Hernia
- Small and large bowel tumors
Diagnosis: while vomiting of the gastric contents in the history suggests an obstruction at the outlet of the stomach, bilious vomiting indicates duodenal, jejunal, ileal and colonic obstructions. The more diffuse and larger the distension that is detected in the abdomen on physical examination, the more distally the obstruction level is. The bellybutton effaces. The distension located in the upper abdomen points to obstruction at the gastric outlet, duodenum and jejunum.
The anus and the perineum must be carefully inspected in order not to skip imperforate anus and cloacal malformations that are among most common cause of the obstructions in neonates. When the abdomen is tense and painful, palpation may not identify a physical finding. However, a palpable lump may indicate tense bowel loop secondary to volvulus, tumor, ascaris plug or invagination.
Radiologic Examination: plain abdominal X-ray (PA view, erect) is the most useful diagnostic tool. The fluid-air interfaces are the sign of the bowel obstruction. The location of the fluid-air interface informs the location of the obstruction. While there is only one fluid-air interface in the obstruction of the gastric outlet, two (double-bubble) and three to 4 fluid-air interfaces are identified in duodenal obstruction and jejuna obstruction, respectively. More fluid-air interfaces should suggest ileal or colonic obstruction. Presence of opaque substance in the lower abdomen is the evidence of peritoneal abscess or perforation. The appearance of unilateral or bilateral subdiaphragmatic air in the form of crescent is the most accurate evidence of the perforated bowel.
Location and cause of the obstruction can be identified with indirect radiology studies by instilling the opaque substance by mouth or rectum. Gastric and duodenal obstructions are clearly identified in obstructions of the upper gastrointestinal system. A colon x-ray may help diagnosis of malrotations, invagination, tumors, colonic duplications and aganglionosis.
Abdominal ultrasound can identify cystic structures (meconium cysts, mesenteric cysts), intra abdominal abscess formations, volvulus, invagination, acute appendicitis, tumors and trico-bezoars due to internal plugs, asgaris plug and obstructions due to lymphomas.
CT and MRI are other diagnostic modalities that can be instituted for detailed examination.
Treatment: it is surgical A nasogastric tube should be placed and fluid and electrolyte therapy should immediately be started when a bowel obstruction due to a reason whatsoever is considered and the patient should be referred to Pediatric Surgery Clinic as soon as possible. All vital signs are quickly monitored in Pediatric Surgery Center and the patient is undergone surgery, after the condition is stabilized. Surgical intervention is performed according to type of the disease.
Early surgical intervention has ultimately reduced the rate of mortality and morbidity.
Advices: patients with abdominal pain, vomiting, distention and inability to discharge gas and stool should be referred to a pediatric surgery center as soon as possible as a bowel construction should be considered.
Prof. Gazi AYDIN, M.D.