Pediatric Small Bowel Obstruction Clinical Presentation

Updated: Oct 27, 2020
  • Author: Pranit Chotai, MD; Chief Editor: Carmen Cuffari, MD  more...
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Presentation

History

The first goal when evaluating children with abdominal pain is to identify life-threatening conditions that require emergent interventions. Bilious vomiting in a neonate is considered malrotation with midgut volvulus until proven otherwise and warrants emergent surgical evaluation. Nonemergent causes of abdominal pain can be identified through deliberate evaluation, beginning with a careful history.

The typical symptoms of small bowel obstruction are abdominal pain, distention, and vomiting. A history of repetitive intermittent abdominal pain with vomiting suggests a chronic, partial small bowel obstruction. Other signs and symptoms that occasionally accompany small bowel obstruction include anorexia, diarrhea (sometimes early in the course of the obstruction), obstipation (common with complete obstructions), hematochezia, and fever (worrisome sign associated with bowel strangulation and necrosis).

Obtain as much history as possible from the child. Seek an accurate chronology of the events. Asking when the child was last completely healthy may help provide an accurate assessment of the child's pathophysiology. In young children, feeding intolerance is often the first change noted by caregivers. Caregivers may describe an infant or small child with abdominal pain as irritable or inconsolable. Pain from a small bowel obstruction is usually colicky. It is typically described as crampy and episodic, persisting for a few minutes at a time. A child with obstructive pain may be unable to remain immobile on the examining table. Constant pain may occur later in the disease course, when strangulation, perforation, or both have occurred. Vomiting caused by a proximal obstruction is usually of gastric content, or it is bilious if the obstruction is distal to the ampulla of Vater. In distal obstructions, vomiting may be feculent.

Obtain a complete past medical history, specifically including information on birth history and any history of trauma, malignancy, radiation, and abdominal surgery.

Additional details regarding the history for frequently encountered diagnoses are provided below.

Intussusception

Intussusception usually causes a sudden onset of severe colicky abdominal pain that often causes a child to draw up both legs. Children appear healthy between paroxysms of pain. As the intussusception progresses, the child becomes progressively more irritable and lethargic. Vomiting occurs in the early phase of the illness and is bilious in 30% of cases. Early in the course of the disease, stools are normal, but they become bloody and mucoid over time.

The classic triad described for intussusception (colicky abdominal pain, a sausage-shaped, palpable abdominal mass, and currant-jelly stools [see the following image]), is actually found in only 20% of cases. Postoperative intussusception occurs within 2-3 weeks after an extensive retroperitoneal dissection (Wilms tumor or neuroblastoma resection, etc). It is usually an ileoileal intussusception, and affected patients lack the palpable mass and rectal bleeding. Patients usually present with crampy abdominal pain, anorexia, bilious vomiting, abdominal distention, and irritability.

Pediatric Small Bowel Obstruction. The clinical ph Pediatric Small Bowel Obstruction. The clinical photograph of a 5-month-old male patient reveals characteristic currant-jelly stools due to intussusception.

Hernia

An incarcerated hernia presents with signs and symptoms of intestinal obstruction (assuming the incarcerated organ is intestine), along with a tender and edematous mass at the site of herniation. A swollen, erythematous mass that becomes erythematous to violaceous and is exquisitely tender usually indicates a strangulated hernia. Fever and toxicity suggest necrosis of the incarcerated organ and possible perforation.

Internal hernias are usually asymptomatic, but when symptoms occur they are often vague. Repeated episodes of colicky abdominal pain and vomiting are common. These symptoms spontaneously subside when the hernia spontaneously reduces. Patients with incarcerated hernias have continuous pain, abdominal distention, fever, nausea, and vomiting. [35]

Malrotation with midgut volvulus

The hallmark of acute midgut volvulus is the sudden onset of bilious vomiting. A careful history may reveal prior feeding problems, with transient episodes of bilious vomiting or failure to thrive. Older children typically describe colicky abdominal pain. Stools are usually absent, but those that do occur yield positive results on guaiac tests. Bright red blood passed through the rectum implies intestinal ischemia.

Postoperative adhesions

Adhesive small bowel obstructions usually cause sudden onset of crampy abdominal pains, followed by anorexia, nausea, and bilious vomiting. Bowel movements and passage of flatus typically cease shortly after symptom onset.

Enteric duplications

The presentation of duplication cysts primarily depends on the type of mucosal lining and cyst location. Some small intestine duplications contain gastric mucosa and manifest with peptic ulceration leading to gastrointestinal hemorrhage. Other cystic duplications may enlarge sufficiently to cause obstructive symptoms; in addition, these cysts may also act as the lead point for an intussusception.

Intestinal atresia and stenosis

Because most atresias (including duodenal atresias) are postampullary, bilious vomiting is the most common presentation. Abdominal distention may be notably absent in more proximal atresias; distention becomes more apparent in infants with more distal obstructions such as ileal atresia.

Necrotizing enterocolitis

The presenting clinical features of necrotizing enterocolitis (NEC) are nonspecific and variable; they include lethargy, temperature instability, feeding intolerance, and abdominal distention. Other common symptoms include bilious vomiting, gross or occult rectal bleeding, abdominal tenderness, and discoloration of the abdominal wall (see the image below). The Bell staging criteria are used to classify the severity of NEC using clinical and radiographic criteria. [36]

Pediatric Small Bowel Obstruction. This clinical i Pediatric Small Bowel Obstruction. This clinical image of a micro-premature baby boy shows discoloration on the right lower quadrant of the abdomen due to intestinal perforation secondary to necrotizing enterocolitis. An umbilical catheter is in place.

Meconium ileus

Infants with meconium ileus typically present with signs of a distal bowel obstruction (usually the terminal ileum), including vomiting (usually bile-stained), failure to pass meconium in the first 48 hours of life, and abdominal distention.

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Physical Examination

On examination, children with small bowel obstructions frequently have abdominal distention. This finding may be notably absent, however, in more proximal obstructions. The abdomen may be tympanic to percussion. On auscultation, obstructions often produce active, high-pitched, and hyperactive bowel sounds with occasional rushes. In infants with thin abdominal walls, peristaltic waves within the bowel proximal to the obstruction can occasionally be visualized on the abdomen.

Abdominal tenderness varies but is typically not dramatic in the absence of compromised bowel. Patients who present late with necrotic bowel and/or perforation will develop signs of peritonitis on examination. In addition, these children may exhibit signs of inadequate perfusion, such as poor capillary refill, tachycardia, decreased urine output, mental status changes, and hypotension as a result of volume depletion from vomiting and third spacing of fluid into the bowel lumen.

Examination must include a careful assessment for signs of hernias that could be the culprit for the obstruction. Depending on the clinical scenario and level of concern for a very distal obstruction, a digital rectal examination may also be warranted.

With intussusception, physical examination occasionally reveals a tender, sausage-shaped mass. Because most intussusceptions are ileocolic, patients may also present with the Dance sign (empty or retracted right lower quadrant).

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