The Choosing Wisely® campaign is an initiative that promotes collaborative conversations between clinicians and families to safely avoid unnecessary and potentially harmful tests.
The American Academy of Paediatrics Section on Emergency Medicine (AAP SOEM) created a list of five key recommendations for Paediatric Emergency Medicine after a structured review process and expert consensus opinion.
This series of DFTB articles aims to increase awareness of the Choosing Wisely® recommendations. Each article will take a deeper dive into each recommendation’s supporting evidence and practical implications.
Do not obtain abdominal radiographs for suspected constipation
The parents of 4-year-old Matthew bring him into the Emergency Department with abdominal pain.
He has not opened his bowels in 5 days, is passing flatus, and you can feel palpable stool on the abdominal examination. You suspect a diagnosis of functional constipation.
Worried about the severity of his constipation, his parents ask you whether an abdominal x-ray would be useful.
What do the guidelines say?
Functional constipation and nonspecific, generalized abdominal pain are common presenting complaints for children in emergency departments. Overall clinical guidelines recommend against obtaining abdominal X-Rays (AXRs) for children diagnosed with functional constipation.
The North American Society for Paediatric Gastroenterology, Hepatology, & Nutrition (NASPGHAN) and the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) have published joint guidance which advises against the routine use of AXRs. Similarly, the National Institute for Health and Care Excellence (NICE) recommends against using AXRs in the UK.
Guidelines recommend that the diagnosis of constipation should be based on the clinical features in the history and examination. The Rome IV criteria are the most widely cited for diagnosing childhood functional constipation.
What is the evidence for avoiding abdominal X-rays?
Although there are guidelines from leading organisations, and the potentially harmful effects of unnecessary radiation exposure are well known, AXRs are widely used in practice. Up to 70% of children diagnosed with constipation in the ED have had an AXR.
The correlation between the severity of constipation and AXR findings is poor. A systematic review observed the sensitivity of AXR for constipation to be as low as 60% and specificity as low as 43%, with no supporting evidence of a potential diagnostic association between clinical symptoms of constipation and faecal loading on AXR. It is also important to remember that any faecal loading seen is subject to daily variation depending on timing and last food intake. The interpretation of radiological findings is subjective. The utility of an AXR for diagnosing constipation is, therefore, limited.
A large retrospective multicentre cohort study involving 282,225 children with constipation across 23 EDs in the USA and Canada reported that AXRs were performed in 65.7% of cases. Children who had an AXR performed for suspected constipation had more re-attendances to the emergency department within three days of the initial visit. Although not causative, the results may reflect diagnostic uncertainty and clinician perception that further tests were required. Misdiagnosed children were likelier to have had an AXR, suggesting that even in children with a relatively large amount of faecal loading, more serious causes of abdominal pain must be excluded.
Another large study involving 3685 children with abdominal pain, undertaken in a single ED in Toronto, Canada, further explored whether using AXRs was associated with misdiagnosis. Misdiagnosed children had more AXRs 75% vs 46%; P = 0.01). Even though children had similar amounts of stool on imaging (P = 0.38), misdiagnosed children also had more abdominal pain (70% vs 49%; P = 0.04) and tenderness (60% vs 32%; P =0.01).
Overall, the evidence shows that AXRs cannot be used to “rule in” constipation or “rule out” alternative diagnoses.
Which children need an abdominal X-ray?
The joint NASPGHAN and ESPGHAN guidelines highlight alarm signs that may point to concerning secondary causes for constipation. These include early life (<1 month) constipation, passage of meconium >48hrs, failure to thrive, specific stool features (ribbon, blood), failure to thrive, bilious vomiting, abnormal anal anatomy, and fear during anal inspection. Abdominal imaging, such as an AXR, may be useful in these cases. After restricting the use of AXR for children with high-yield clinical features (prior abdominal surgery, foreign body ingestion, abnormal bowel sounds, abdominal distension, peritoneal signs), a prospective study of 344 children demonstrated a 38% reduction in overall AXR use with no significant harm or missed diagnoses.
How can we reduce the use of radiographs?
A Quality Improvement Project (QIP) explored how the introduction of local evidence-based guidance can reduce the use of AXRs in constipation. The project, conducted over a 7-year period and including 6723 children with constipation, aimed to decrease the percentage of patients undergoing AXR for constipation during the Paediatric Gastroenterology outpatient review. After introducing local guidance, AXR use decreased by over 50% without adverse effects.
Although taking place in a specialist outpatient setting, this QIP demonstrated the impact of adopting local guidance to promote culture and practice change. This could be an important first step forward to reduce AXR use in the emergency department.
What should we say to parents and caregivers?
When a large group of 305 PEM clinicians were surveyed on their reasons for obtaining an AXR for constipation, obtaining family buy-in was the most common (44%). Given the risks (misdiagnosis and radiation dosage) and costs associated with AXRs, communication to reach a point of mutual understanding with parents and carers is vital.
A shared understanding of the limited role of imaging can be gained by discussing the clinical diagnosis, how AXRs are not useful in ruling in constipation or ruling out serious pathology, how findings correlate poorly with clinical severity, and how imaging may cause harm through the risk of misdiagnosis and increased radiation exposure. Discussion may be supported by patient information leaflets in multiple languages.
Take home points
Also, take a look at…
Anwar Ul Haq MM, Lyons H, Halim M. Pediatric Abdominal X-rays in the Acute Care Setting – Are We Overdiagnosing Constipation?. Cureus. 2020;12(3):e7283. Published 2020 Mar 15. doi:10.7759/cureus.7283
Beinvogl B, Sabharwal S, McSweeney M, Nurko S. Are We Using Abdominal Radiographs Appropriately in the Management of Pediatric Constipation?. J Pediatr. 2017;191:179-183. doi:10.1016/j.jpeds.2017.08.075
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. DOI: https://doi.org/10.1016/j.jpeds.2011.12.045
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. DOI: https://doi.org/10.1016/j.jpeds.2017.03.061
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
Hoskins B, Marek S. Things We Do for No Reason™: Obtaining an Abdominal X-ray to Assess for Constipation in Children. J Hosp Med. 2020;15(9):557-559. doi:10.12788/jhm.3387
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. DOI: 10.1097/PEC.0000000000001549
McSweeney ME, Chan Yuen J, Meleedy-Rey P, Day K, Nurko S. A Quality Improvement Initiative to Reduce Abdominal X-ray use in Pediatric Patients Presenting with Constipation. J Pediatr. 2022;251:127-133. doi:10.1016/j.jpeds.2022.07.016
NICE. Constipation in children and young people: diagnosis and management. NICE. Clinical guideline [CG99] Published: 26 May 2010 Last updated: 13 July 2017. Available online at https://www.nice.org.uk/guidance/cg99
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. DOI: https://doi.org/10.1097/MPG.0b013e3181cb4309
Reuchlin-Vroklage LM, Bierma-Zeinstra S, Benninga MA, Berger MY. Diagnostic value of abdominal radiography in constipated children: a systematic review. Arch Pediatr Adolesc Med. 2005;159(7):671-678. doi:10.1001/archpedi.159.7.671
Rothrock SG, Green SM, Hummel CB. Plain abdominal radiography in the detection of major disease in children: a prospective analysis. Ann Emerg Med. 1992;21(12):1423-1429. doi:10.1016/s0196-0644(05)80053-8
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. DOI: https://doi.org/10.1097/mpg.0000000000000266