Things We Do for No Reason™: Obtaining an Abdominal X-ray to Assess for Constipation in Children

Inspired by the ABIM Foundation’s Choosing Wisely^® campaign, the “Things We Do for No Reason^™” (TWDFNR) series reviews practices that have become common parts of hospital care but may provide little value to our patients. Practices reviewed in the TWDFNR series do not represent clear-cut conclusions or clinical practice standards but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion.

A 5-year old boy is admitted to the hospital for a bowel clean-out after presenting with abdominal pain and having an abdominal x-ray that demonstrated a “moderate stool burden.” After ingestion of the bowel prep, he develops worsening abdominal cramping and diarrhea. Upon reviewing the bowel history with his mother afterward, the team learns that he has had a bowel movement every 1-2 days as usual and has been having soft stools without any straining, pain, or blood present.

Functional constipation is a common clinical problem in pediatrics and constitutes a large number of admissions into hospitals and visits to clinics and emergency departments. In the United States, up to 36% of children are affected.Associated healthcare costs for children with constipation are estimated at $5.9 billion per year, which is $3.9 billion more than the general pediatric population without constipation.¹ In 2011, American children aged 17 years and younger had more than 270,000 visits to the emergency department for constipation.² As many as 70% of children who are given a diagnosis of constipation in the emergency department have an abdominal x-ray completed.³ The carcinogenic effects of radiation from radiography are well known. Unnecessary imaging places the child at risk for these effects while adding to the overall cost of medical care.⁴

The overall utilization of diagnostic imaging is increasing in pediatric emergency departments.⁴ When questioning why this is the case, one should consider the method of problem solving used by most physicians. After formulating initial hypotheses based on available information, prior knowledge, and experience, physicians aim to obtain additional data to confirm or reject each hypothesis.⁵Despite evidence that abdominal x-ray findings correlate poorly with clinical severity of constipation, radiography is widely available and may be thought of as a cheap and noninvasive means to further investigate. Physicians may believe that an x-ray will allow for quantification of stool in the colon, thereby supporting or refuting one of the hypotheses. In this way, an x-ray can be thought of as a confirmatory test for constipation. In children that have a history of constipation, physicians may seek to obtain an x-ray to assess for the severity of constipation or for improvement from a previous image.

A 2017 study surveyed 24 pediatric gastroenterologists after 72 patient encounters and found that the most common cause for obtaining an abdominal x-ray was for evaluation of stool burden (70%).⁵ Other reasons included assessing the need for a bowel clean-out (35%), diagnosing fecal impaction (27%), finding the cause for abdominal pain (24%), and demonstrating stool burden to a family (14%). This same study found that most of the polled providers used an abdominal x-ray to assess for constipation, and nearly half changed their management based on the findings. The study found that confidence levels were significantly higher after obtaining an x-ray, which likely indicates an internal need to boost the level of confidence in diagnosis and therapy.⁵