This is a blog post designed to disseminate the important work of Choosing Wisely, an initiative of the the American Board of Internal Medicine Foundation, the goal of which is the spark conversations between clinicians and patients about what tests, treatments, and procedures are needed – and which ones are not.

Special thanks to Dr. Stephen Freedman, from the University of Calgary, for reviewing this post as well – he brought some practical feedback to the table.

Learning Objectives

1. Understand that an abdominal radiograph will not give accurate findings for degree of constipation
2. Understand that findings on an abdominal radiograph may lead to a missed diagnosis of a more serious condition
3. Understand when an abdominal radiograph may be necessary in a patient with constipation and abdominal pain

Functional constipation and nonspecific, generalized abdominal pain are common presenting complaints for children in emergency departments. Constipation is a clinical diagnosis and does not require testing, yet as many as 70% of children who are given a diagnosis of constipation in the emergency department have an abdominal x-ray completed.  The diagnosis of constipation should be made based on a good history and clinical exam. Use of abdominal radiographs has been associated with increased diagnostic errors. 

Reasons to not order an abdominal radiograph to diagnose constipation include

• Lack of standardization and subjectivity and wide normal variation result in poor sensitivity and specificity of abdominal radiographs to diagnose constipation
• No evidence for a diagnostic association between clinical symptoms of constipation and fecal loading on abdominal x-rays.
• Use of abdominal radiographs to diagnose constipation has been associated with increased diagnostic error, possibly due to the cognitive bias of search satisfaction. 
• Associated with missed diagnoses, false reassurance of constipation, more frequent admissions into the hospital, longer hospital stays, higher healthcare costs, and unnecessary radiation exposure.
• Clinical guidelines recommend against obtaining routine abdominal radiographs in patients with clinical diagnosis of functional constipation.
• Increased Clinician time, and increased length of stay in the emergency department
• Cost of obtaining and unnecessary test 

There are three main reasons to consider getting an X-Ray – if you are concerned about:

• Obstruction
• Perforation
• Foreign body ingestion

Sometimes there are specific indications to order diagnostic evaluation, but an abdominal X-Ray may not be the best test:

Messaging for patients and families

When constipation leads to a child not being able to move their bowels, they may experience pain.  However, many other conditions can cause abdominal pain.When children have abdominal pain it can be caused by constipation.  If you bring your child to the emergency department they will ask you questions about the abdominal pain including frequency of stooling and consistency of the stool to help determine if constipation could be the cause.  Because normal intestines produce a lot of stool, an xray doesn’t show whether or not a child is actually constipated.  Xrays don’t help in figuring out whether or not a child is constipated and can sometime lead to incorrect conclusions about where pain is coming from.

Messaging for colleagues and consultants

Despite the widespread belief that constipation may cause generalized and nonspecific abdominal pain, the association of abdominal pain and functional constipation is not well-established.  In fact, Rome IV diagnostic criteria for functional constipation in children do not include presence of pain.  While obtaining an abdominal x-ray in patients with abdominal pain constipation is associated with diagnostic error, probably because of the false sense of having found an explanation for pain. It may make you reassured that constipation is the diagnosis, but this is a false sense of reassurance. Guidelines from gastroenterology societies do not recommend obtaining an abdominal radiograph as they are not sensitive nor specific in diagnosing constipation and degree of symptoms does not correlate with amount of stool seen on the x-ray.  In a portion of cases a false diagnosis is given of constipation resulting in missed diagnoses and increased return visits. The diagnosis of constipation or fecal impaction should be made primarily by history and physical examination, augmented by a digital rectal examination when indicated. 

Do not obtain abdominal radiographs for suspected constipation

This episode of PEM Currents: The Pediatric Emergency Medicine Podcast approaches the topic from another angle and also discusses how we can avoid overuse of abdominal X-rays in constipation.

 

Metabolic Disorders – PEM Currents: The Pediatric Emergency Medicine Podcast

This episode will help you better prepare for and manage children with inborn errors of metabolism in the Emergency Department. Consider it a supplement to what you remember from Biochemistry and the instructions on the family’s laminated care plan sheet. My special guest podcaster, Emily Groopman, is an actual Pediatric Geneticist in training and we […]

1. Metabolic Disorders 16:57
2. Vitamin K Deficient Bleeding (Hemorrhagic disease of the newborn) 13:32
3. Cellulitis 14:28
4. Laryngomalacia 11:34
5. Meckel Diverticulum 07:05

References

Freedman SB, Rodean J, Hall M, et al. Delayed diagnoses in children with constipation: multicenter retrospective cohort study. J Pediatr. 2017;186:87-94.e16. PMID: 28457526.

Pensabene L, Buonomo C, Fishman L, Chitkara D, Nurko S. Lack of utility of abdominal x-rays in the evaluation of children with constipation: Comparison of different scoring methods. J Pediatr Gastroenterol Nutr. 2010;51(2):155-159. PMID: 20453675.

Berger MY, Tabbers MM, Kurver MJ, Boluyt N, Benninga MA. Value of abdominal radiography, colonic transit time, and rectal ultrasound scanning in the diagnosis of idiopathic constipation in children: a systematic review. J Pediatr. 2012;161(1):44–50.e502. PMID: 22341242.

Tabbers MM, DiLorenzo C, Berger MY, et al. Evaluation and treatment of functional constipation in infants and children: Evidence-based recommendations from ESPGHAN and NASPGHAN. J Pediatr Gastroenterol Nutr. 2014;58(2):258-274. PMID: 24345831.

Kearney R, Edwards T, Braford M, Klein E. Emergency provider use of plain radiographs in the evaluation of pediatric constipation. Pediatr Emerg Care. 2019;35(9):624-629. PMID: 30045349.

Freedman SB, Thull-Freedman J, Manson D, et al. Pediatric abdominal radiograph use, constipation, and significant misdiagnoses. J Pediatr. 2014;164(1):83-88.e2. PMID: 24128647.