Review Question - QID 103551

The patient has symptoms most consistent with intussusception. The next and most sensitive and specific diagnostic test would be an abdominal ultrasound.

Intussusception is a process where a segment of the intestine slides into the adjacent intestinal lumen causing bowel obstruction. A combination of abdominal pain, "currant-jelly" stools (blood and mucous), vomiting, and an abdominal mass suggest intussusception. The best initial diagnostic test is an abdominal ultrasound; however, despite being less sensitive and specific, abdominal radiographs may also reveal intussusception.

Leung et al. discuss the ways to differentiate between abdominal pain and obstruction in children. Intussusception occurs more commonly in ages 0-5 years old and presents with the classic "currant-jelly" stool that differentiates it from bloody diarrhea seen in inflammatory bowel disease and the classic diarrhea in gastroenteritis or food poisoning. Intussusception causes intestinal obstruction, thus one should look for bilious vomiting as a suggestive sign.

Rohrschneider explains that most cases of intussusception are idiopathic without a lead point and ultrasound is the initial method utilized to exclude diagnosis. Visualizing the target sign in transverse view and pseudokidney sign in longitudinal view are pathognomonic in imaging. Alternatively, the article explains that barium enema under flouroscopic control, pneumatic reduction under flouroscopic monitoring, and sonographically guided hydrostatic reduction with normal saline solution are imaging methods both diagnostic and curative.

Illustration A demonstrates the 'target sign' seen on ultrasound in cases of intussusception.

Incorrect answers:
Answer 1: Peripheral blood culture is not correct because this is intussusception rather than infection causing abdominal pain.
Answer 2: Kidney, ureter, bladder radiographs may discover intussusception; however, it is not as sensitive or specific as abdominal ultrasound.
Answer 3: Complete blood count with differential would aid in discovering infection but would not be helpful in the evaluation of intussusception.
Answer 5: Exploratory laparotomy would not be the initial step in evaluating intussusception, but would aid in surgical correction if irreducible with traditional non-surgical methods.