European Journal of Cardiovascular Medicine

Paediatric acute abdominal pain is a common emergency presentation and spans a wide spectrum from self-limited conditions to rapidly progressive surgical disease. The clinical picture is often nonspecific, especially in neonates and infants, where communication barriers and limited physiological reserve increase the risk of delayed recognition of peritonitis, strangulation, or perforation. Because delayed presentation is associated with dehydration, electrolyte derangements, sepsis, and bowel compromise, an organised assessment combining bedside examination with targeted imaging remains central to early triage.

Ultrasonography has become a cornerstone in the evaluation of the paediatric acute abdomen as it is portable, repeatable, and free of ionising radiation, while offering real-time assessment of bowel, appendix, peritoneal fluid, and vascular flow patterns [1]. In many low- and middle-income settings, ultrasound is frequently the first advanced modality available after clinical assessment and plain radiography, and it can identify a range of surgically relevant entities including intussusception, appendicular inflammation, and free fluid [2]. Plain abdominal radiography, although limited for aetiological diagnosis, remains useful for detecting obstruction patterns, pneumoperitoneum, and gross bowel dilatation, thereby guiding resuscitation and urgent surgical decision-making.

Acute appendicitis and its complications remain a leading indication for emergency paediatric surgery, and diagnostic imaging is routinely used to reduce negative appendectomy and avoid treatment delays. Meta-analytic evidence has demonstrated high diagnostic performance for both ultrasonography and computed tomography for appendicitis, while emphasising the importance of radiation risk considerations in children [3]. Accordingly, paediatric radiology guidance supports an ultrasound-first approach with selective use of cross-sectional imaging, tailored to clinical risk, body habitus, and local expertise [4]. Hospital-level variation in imaging utilisation and accuracy has also been reported, influencing computed tomography exposure and diagnostic timelines for children with suspected appendicitis [5,6].

Alongside appendicitis, other important surgical causes include intestinal obstruction due to bands/adhesions, intussusception, malrotation with volvulus, Hirschsprung disease, and perforation peritonitis. Each condition presents with overlapping symptoms, while imaging offers differentiation and helps prioritise operative urgency. Despite the central role of first-line imaging, locally relevant data describing the combined clinical and radiological spectrum of paediatric suspected surgical abdomen-correlated with intraoperative diagnosis and early postoperative outcomes-remain limited. Documenting these patterns is useful for developing pragmatic imaging pathways, training priorities, and counselling families regarding expected operative findings and complications.

Objectives: (i) To describe the demographic and clinical profile of paediatric patients presenting with suspected surgical abdomen; (ii) to document radiological findings on initial plain radiography and ultrasonography; (iii) to assess concordance between initial imaging impression and intraoperative diagnosis; and (iv) to report immediate postoperative outcomes and complications.

Study design and setting: This hospital-based observational study was conducted in the Departments of Paediatrics, General Surgery and Radiology at Azeezia Institute of Medical Sciences and Research, Kollam, Kerala, India, over one year (January 2022 to December 2022). Institutional ethics committee approval was obtained prior to enrolment, and written informed consent was taken from parents or legal guardians.

Participants and eligibility: Consecutive children aged 0-12 years presenting to emergency services with suspected surgical abdomen and subsequently taken up for emergency operative management were included until a sample size of 50 was achieved. Suspected surgical abdomen was defined as acute abdominal pain or abdominal distension with clinical features suggestive of intestinal obstruction, peritonitis, or appendicular pathology requiring surgical evaluation. Children with abdominal trauma, predominantly medical abdominal pain (e.g., gastroenteritis without surgical suspicion), or incomplete imaging/operative records were excluded.

Clinical assessment and perioperative management: Baseline demographic details, symptom duration, and key presenting complaints (pain, vomiting, distension, constipation/failure to pass stools, fever, and bilious vomiting) were recorded using a structured proforma. Examination findings included hydration status, abdominal tenderness, guarding/rigidity, palpable mass, and signs of shock. Initial management followed institutional emergency protocols (nil per oral, intravenous fluids, nasogastric decompression when indicated, analgesia, and empiric antibiotics after assessment).

Radiological assessment: All enrolled children underwent plain abdominal radiography and focused abdominal ultrasonography as first-line investigations, consistent with established paediatric imaging practice [1,2]. Radiographs were assessed for multiple air-fluid levels, bowel loop dilatation, absence of distal gas, and pneumoperitoneum. Ultrasonography was performed by a radiologist using graded compression and Doppler assessment when required. For suspected appendicitis, the imaging strategy aligned with ultrasound-first pathways and selective escalation principles described in the literature [3-6]. Ultrasound features used to support complicated appendicitis included periappendiceal collection, marked free fluid, and loss of wall integrity [7,8]. Intussusception was identified by the target/doughnut sign or pseudokidney appearance, consistent with evidence supporting high diagnostic accuracy of ultrasound for intussusception [9-11]. Suspicion of malrotation with volvulus was based on abnormal mesenteric vessel relationship and/or the whirlpool sign [12]. When Hirschsprung disease was clinically suspected, contrast enema was performed as per unit protocol to support surgical planning [13]. In neonates with suspected obstruction, interpretation was informed by pattern-based radiographic assessment described in neonatal imaging literature [14].

Operative correlation and outcomes: Intraoperative findings were recorded as the final surgical diagnosis. Radiology-surgery concordance was defined as agreement between the principal radiological impression and the intraoperative diagnosis. Postoperative outcomes included surgical site infection, prolonged ileus, sepsis, re-exploration, mortality, and length of hospital stay.

Statistical analysis: Data were entered in Microsoft Excel and analysed using SPSS (version 26). Categorical variables are presented as frequency and percentage; continuous variables are presented as mean ± standard deviation. Radiology-operative concordance is presented as percentage agreement.

A total of 50 paediatric patients with suspected surgical abdomen who underwent emergency operative management were included. The mean age was 4.6 ± 3.2 years (range: 2 days-12 years), with the 1-5-year age group forming the largest subgroup (36.0%). Males constituted 32 (64.0%) of the cohort. Most children presented after the first day of symptoms, and 19 (38.0%) presented beyond 48 hours (Table 1).

Table 1. Demographic profile of study participants (n = 50)

Abdominal pain (84.0%) and vomiting (76.0%) were the most frequent presenting symptoms. Abdominal distension was noted in 60.0% and constipation/failure to pass stools in 52.0%. On examination, dehydration was present in 40.0%, guarding/rigidity in 32.0%, and a palpable abdominal mass in 18.0% (Table 2).

Table 2. Clinical presentation and examination findings (n = 50)

Figure 1: Clinical presentation and examination findings

Plain abdominal radiography demonstrated multiple air-fluid levels in 56.0% and dilated bowel loops in 44.0%. Absence of distal gas was observed in 30.0%, while pneumoperitoneum was detected in 8.0%. On ultrasonography, intussusception was suggested in 20.0% and dilated bowel loops with reduced peristalsis in 28.0%. Free intraperitoneal fluid was seen in 24.0%, and appendicular pathology in 12.0%. Overall, 16.0% of ultrasound examinations were non-diagnostic (Table 3).

Table 3. Radiological findings on initial imaging (n = 50)

At surgery, intussusception (24.0%) and obstruction due to adhesions/bands (20.0%) were the leading diagnoses, followed by complicated appendicitis (16.0%) and malrotation with volvulus (12.0%). Perforation peritonitis and Hirschsprung disease accounted for 10.0% each. Initial imaging impressions were concordant with intraoperative diagnosis in 41 cases (82.0%) (Table 4).

Table 4. Intraoperative diagnosis and correlation with radiology (n = 50)

Figure 2: Intraoperative diagnosis and correlation with radiology

Radiological findings were concordant with intraoperative diagnosis in 41 cases (82.0%). Ultrasonography showed higher diagnostic yield for intussusception and appendicular pathology, whereas plain radiography was more informative for obstruction patterns and perforation.

Postoperative recovery was uneventful in 38 children (76.0%). Surgical site infection occurred in 12.0%, prolonged ileus in 8.0%, and sepsis in 6.0%. Two children (4.0%) required re-exploration and two (4.0%) died. The mean hospital stay was 7.8 ± 3.6 days (Table 5).

Table 5. Postoperative outcomes and complications (n = 50)

This tertiary care observational study describes the clinical spectrum, first-line imaging profile, and operative correlation among 50 children undergoing emergency surgery for suspected surgical abdomen. The cohort was predominantly male and young, with more than two-thirds presenting after 24 hours and over one-third beyond 48 hours, highlighting persisting referral and access delays. Such delays are clinically significant because dehydration and sepsis evolve rapidly in children, and bowel compromise can occur in obstruction and volvulus.

The symptom triad of abdominal pain, vomiting, and distension dominated our series, reflecting a broad overlap across obstruction and inflammatory etiologies. This reinforces the value of imaging adjuncts for aetiological diagnosis and prioritisation. Ultrasound is widely recommended as an initial modality in the paediatric acute abdomen because it provides rapid, radiation-free, repeatable information and can be applied during resuscitation [1]. Experience from similar settings has shown ultrasound to be particularly useful when interpreted alongside clinical suspicion and radiography, while acknowledging operator dependence [2].

In our cohort, plain radiography was informative for obstruction patterns and free air, whereas ultrasonography more often suggested specific causes such as intussusception and appendicular disease. Operative diagnoses were led by intussusception and adhesive/band obstruction. Ultrasound has well-documented accuracy for intussusception, and evidence synthesis supports high sensitivity and specificity for radiologist-performed examinations [10,11]. Clinical practice updates also emphasise the role of ultrasound in directing reduction strategies and identifying children who require operative intervention because of bowel compromise or failed reduction [9].

Complicated appendicitis represented 16% of cases. The ultrasound-first strategy for suspected appendicitis is supported by meta-analytic evidence and paediatric imaging guidance that balance diagnostic performance with radiation safety considerations [3,4]. Studies have described substantial inter-hospital variation in imaging utilisation and diagnostic accuracy, influencing computed tomography exposure and care pathways [5,6]. In addition, ultrasound features can assist risk stratification for complicated appendicitis, including periappendiceal collections and prominent free fluid, which aligns with published paediatric surgical evidence [7,8].

Malrotation with volvulus accounted for 12% of operative diagnoses. The whirlpool sign remains an important sonographic clue and should prompt urgent surgical attention because ischemia can develop quickly [12]. Hirschsprung disease and perforation peritonitis were also notable in our series; targeted contrast studies, when clinically appropriate, can support diagnostic planning in Hirschsprung disease [13], while radiography retains value for perforation detection.

Overall, imaging concordance with operative diagnosis was high (82%), indicating that combined interpretation of symptoms, examination, and first-line imaging can reliably guide emergency decision-making in a tertiary care setting. Service-level improvements that reduce delays to presentation and strengthen standardised ultrasound protocols could further decrease postoperative infectious morbidity and sepsis, particularly in children presenting after prolonged symptom duration.

Limitations

This was a single-centre study with a small sample and included only children who proceeded to emergency surgery, limiting inference to conservatively managed acute abdomen. Imaging was restricted to radiography and ultrasonography, and ultrasound interpretation depended on operator skill and equipment. Percentage concordance does not provide sensitivity or specificity estimates. Follow-up ended at discharge, so late complications and readmissions were not captured.

In this tertiary care cohort of children undergoing emergency surgery for suspected surgical abdomen, many presented beyond the first day of symptoms and commonly had abdominal pain with vomiting and distension. Plain radiography rapidly highlighted obstruction patterns and occasional pneumoperitoneum, while ultrasonography contributed aetiological diagnosis in a substantial proportion, especially for intussusception and appendicular pathology. Initial imaging impressions showed high concordance with intraoperative findings, supporting an integrated clinical-radiological approach in emergency paediatric surgery. Given the observed postoperative infections, ileus, and sepsis, strengthening early referral and preoperative optimisation remains essential. Focused ultrasound training and protocol-driven imaging can further improve diagnostic confidence and streamline emergency operative decision-making in similar settings across centres

1. Babcock DS. Sonography of the acute abdomen in the pediatric patient. J Ultrasound Med. 2002;21(8):887-899. doi:10.7863/jum.2002.21.8.887.
2. Mishra DS, Magu S, Sharma N, Rattan KN, Tewari AD, Rohilla S. Imaging in acute abdomen. Indian J Pediatr. 2003;70(1):15-19. doi:10.1007/BF02722736.
3. Doria AS, Moineddin R, Kellenberger CJ, Epelman M, Beyene J, Schuh S, et al. US or CT for diagnosis of appendicitis in children and adults? A meta-analysis. Radiology. 2006;241(1):83-94. doi:10.1148/radiol.2411050913.
4. Doria AS. Optimizing the role of imaging in appendicitis. Pediatr Radiol. 2009;39(Suppl 2):S144-S148. doi:10.1007/s00247-008-1105-5.
5. Saito JM, Yan Y, Evashwick TW, Warner BW, Tarr PI. Use and accuracy of diagnostic imaging by hospital type in pediatric appendicitis. Pediatrics. 2013;131(1):e37-e44. doi:10.1542/peds.2012-1665.
6. Kotagal M, Richards MK, Flum DR, Acierno SP, Weinsheimer RL, Goldin AB. Use and accuracy of diagnostic imaging in the evaluation of pediatric appendicitis. J Pediatr Surg. 2015;50(4):642-646. doi:10.1016/j.jpedsurg.2014.09.080.
7. Gonzalez DO, Lawrence AE, Cooper JN, Sola R Jr, Garvey E, Weber BC, et al. Can ultrasound reliably identify complicated appendicitis in children? J Surg Res. 2018;229:76-81. doi:10.1016/j.jss.2018.03.012.
8. Eng KA, Abadeh A, Ligocki C, Lee YK, Moineddin R, Adams-Webber T, Schuh S, Doria AS. Acute Appendicitis: A Meta-Analysis of the Diagnostic Accuracy of US, CT, and MRI as Second-Line Imaging Tests after an Initial US. Radiology. 2018 Sep;288(3):717-727. doi: 10.1148/radiol.2018180318. Epub 2018 Jun 19. PMID: 29916776.
9. Kim PH, Hwang J, Yoon HM, Lee JY, Jung AY, Lee JS, Cho YA. Predictors of failed enema reduction in children with intussusception: a systematic review and meta-analysis. Eur Radiol. 2021 Nov;31(11):8081-8097. doi: 10.1007/s00330-021-07935-5. Epub 2021 May 11. PMID: 33974147.
10. Li XZ, Li D, Zhang H, Jia H, Liu J, Wu J, et al. Ultrasonographic diagnosis of intussusception in children: a systematic review and meta-analysis. Clin Exp Emerg Med. 2020;7(4):316-324. doi:10.15441/ceem.20.029.
11. Tsou PY, Wang YH, Ma YK, Deanehan JK, Gillon J, Chou EH, Hsu TC, Huang YC, Lin J, Lee CC. Accuracy of point-of-care ultrasound and radiology-performed ultrasound for intussusception: A systematic review and meta-analysis. Am J Emerg Med. 2019 Sep;37(9):1760-1769. doi: 10.1016/j.ajem.2019.06.006. Epub 2019 Jun 4. PMID: 31182360.
12. Pracros JP, Sann L, Genin G, Tran-Minh VA, Morin de Finfe CH, Foray P, Louis D. Ultrasound diagnosis of midgut volvulus: the "whirlpool" sign. Pediatr Radiol. 1992;22(1):18-20. doi:10.1007/BF02011603.
13. Frongia G, Günther P, Schenk JP, Strube K, Kessler M, Mehrabi A, Romero P. Contrast enema for Hirschsprung disease investigation: diagnostic accuracy and validity for subsequent diagnostic and surgical planning. Eur J Pediatr Surg. 2016;26(2):207-214. doi:10.1055/s-0035-1546755.
14. Carroll AG, Kavanagh RG, Ni Leidhin C, Cullinan NM, Lavelle LP, Malone DE. Comparative Effectiveness of Imaging Modalities for the Diagnosis of Intestinal Obstruction in Neonates and Infants:: A Critically Appraised Topic. Acad Radiol. 2016 May;23(5):559-68. doi: 10.1016/j.acra.2015.12.014. Epub 2016 Feb 5. PMID: 26857524.