Ultrasonographic diagnosis and laparoscopic bowel-preserving management of ileal obstruction caused by water bead ingestion in a toddler: a case description

Introduction

Water beads, also known as superabsorbent polymer beads or hydrogel beads, are increasingly recognized as a pediatric ingestion hazard. Their small dehydrated size, bright appearance, and marked expansion after fluid absorption make them particularly concerning for infants and toddlers. Recent epidemiologic data have shown that pediatric water bead-related emergency department (ED) visits are increasing rapidly, with children younger than 5 years most commonly affected (1). This increase should be interpreted in context: most reported exposures do not result in clinically significant bowel obstruction, and many children remain asymptomatic or do not require imaging or intervention. Ultrasonography has been repeatedly reported as a particularly useful modality for identifying radiolucent foreign bodies in symptomatic children, whereas conventional radiography and computed tomography (CT) may reveal only secondary signs of bowel obstruction (2,3).

Most previously reported cases of obstructive water bead ingestion have required operative intervention, often involving open surgery or enterotomy. More recently, small series have suggested that manual fragmentation and distal advancement may avoid enterotomy in carefully selected patients (4). However, reports of successful laparoscopic bowel-preserving management after preoperative formal sonographic suspicion remain limited. Herein, we describe the case of a toddler with ileal obstruction caused by water bead ingestion in whom ultrasonography provided the decisive preoperative clue and laparoscopic fragmentation enabled spontaneous postoperative evacuation without enterotomy.

Case presentation

A 2-year-old boy was admitted to Gansu Provincial Maternity and Child-care Hospital because of progressive abdominal distension, abdominal pain, persistent vomiting, and intestinal obstruction after accidental ingestion of a water bead.

According to the family, the child ingested a water bead 4 days before admission. Vomiting began on the second day after ingestion. During the 3 days before admission, the vomiting increased to approximately 10 episodes per day and was accompanied by obvious abdominal distension and absence of spontaneous flatus or defecation. The vomitus consisted of gastric contents without yellow-green bilious material. He was initially evaluated at a local hospital, where abdominal radiography showed intestinal gas accumulation and intestinal obstruction. Two glycerin enemas were administered, resulting in only a small amount of loose watery stool. Intravenous fluid replacement and antiemetic therapy were given, but no obvious clinical improvement was observed.

On admission to our center, the child appeared lethargic and fatigued, and the abdominal distension had worsened. His temperature was 37.6 ℃, heart rate 128 beats/min, respiratory rate 40 breaths/min, blood pressure 88/42 mmHg, and pulse oxygen saturation 96%. He had sunken eyes, decreased skin turgor, scant tears during crying, and reduced urine output, consistent with dehydration. Capillary refill time was 2 seconds. His height was 95 cm and weight was 13.5 kg. Abdominal examination revealed marked distension and obvious abdominal pain. Bowel sounds were decreased. No rebound tenderness or muscular guarding was present. The child had no significant previous medical history and no history of abdominal surgery.

Venous blood gas analysis on admission showed pH 7.39, partial pressure of oxygen 72.2 mmHg, oxygen saturation 92.4%, potassium 4.37 mmol/L, sodium 136.1 mmol/L, lactate 2.17 mmol/L, and total carbon dioxide 15.1 mmol/L. Peripheral blood examination revealed a white blood cell count of 12.35×10⁹/L, neutrophil percentage of 72.9%, and C-reactive protein level of 12.39 mg/L. Norovirus, rotavirus, and adenovirus antibody tests were all negative.

Plain abdominal radiography demonstrated bowel gas accumulation and dilated bowel loops, consistent with intestinal obstruction (Figure 1). Abdominal CT also showed bowel dilatation, but no definite foreign body was visualized (Figure 2). A formal abdominal ultrasound examination was performed in the Department of Ultrasound Center by an ultrasound physician. Ultrasonography revealed a round intraluminal anechoic lesion measuring approximately 3.0 cm in diameter (Figure 3). The lesion showed echogenicity similar to adjacent bowel contents internally, with a thin hyperechoic capsule-like rim forming a nearly perfect circular contour. No posterior acoustic shadowing was observed, and posterior acoustic enhancement was not evident on the stored images. Color Doppler imaging was not performed during this examination. Based on this unusual sonographic appearance, an expanded intraluminal foreign body was suspected. Further targeted questioning of the family then revealed that dry water beads, originally measuring approximately 0.5 cm in diameter, had been bought for or used by the patient’s 6-year-old brother and were available in the household.

The child was transferred to the pediatric surgery service and underwent laparoscopic exploration. No preoperative nasogastric decompression was documented before surgery. Intraoperatively, a spherical intraluminal foreign body was identified in the mid-ileum (Figure 4). The remaining bowel was carefully inspected, and no other intraluminal foreign bodies were found. The bowel wall around the obstruction was viable, without perforation, ischemic discoloration, necrosis, or severe inflammatory edema. The obstructing lesion was soft, compressible, and could be gently advanced distally into the ascending colon without serosal injury. Since the preoperative sonographic findings strongly suggested a water bead, and because the lesion could be manipulated safely, enterotomy was avoided. Instead, the bead was manually compressed and completely fragmented. The total operative time was 15 minutes, and no blood loss occurred.

On postoperative days 2 and 3, the child passed large amounts of fragmented water bead material mixed with stool (Figure 5). Follow-up ultrasonography on postoperative day 4 showed patent bowel without evidence of residual obstruction (Figure 6), and oral feeding was resumed thereafter. By postoperative day 5, the child was alert, able to play freely, had normal urine output and bowel movements, and showed clear clinical recovery. Repeat laboratory examination showed a white blood cell count of 5.3×10⁹/L, neutrophil percentage of 18.5%, and C-reactive protein level of 3.37 mg/L. He was discharged in good condition. At 2-week follow-up, he remained completely asymptomatic and clinically normal.

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was provided by the patient’s legal guardians for publication of this case description and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

This case is notable for three main reasons. First, ultrasonography provided the key preoperative diagnostic clue when plain radiography and CT failed to identify a definite foreign body. Second, the obstructing lesion was managed laparoscopically without enterotomy. Third, postoperative spontaneous evacuation confirmed successful bowel-preserving treatment.

Water bead ingestion is an increasingly recognized hazard in young children, but the clinical risk should be framed carefully. Recent epidemiologic analysis has shown a rapid rise in pediatric water bead-related ED visits, particularly in children younger than 5 years (1). However, clinically significant bowel obstruction is rare relative to the total number of exposures, and most children evaluated after exposure remain asymptomatic and do not require imaging, endoscopic treatment, or surgery. In the present case, the dry bead was approximately 0.5 cm in diameter before expansion, which is larger than many commonly marketed small water beads measuring approximately 2–3 mm. This size difference may have contributed to the obstruction risk and should prevent overgeneralization of this case to all water bead ingestions. A literature review summarized 43 cases of bowel obstruction caused by superabsorbent polymer beads, and a recent pediatric retrospective series further emphasized intestinal obstruction as one of the most important complications in symptomatic or obstructed patients (4,5). In addition to clinical concerns, public health agencies have issued safety warnings because water beads may look like candy, expand markedly after fluid exposure, and cause internal injury if ingested (6).

In the present case, radiography and CT demonstrated bowel obstruction but did not directly reveal the foreign body. A formal ultrasound examination performed by an ultrasound physician identified a round intraluminal anechoic lesion with a thin hyperechoic rim. This appearance is consistent with previous reports describing water beads as rounded, well-defined, cyst-like intraluminal lesions on ultrasound (2,3). The differential diagnosis of an intraluminal cystic-appearing lesion may include enteric duplication cyst and other cystic bowel lesions. However, enteric duplication cysts usually demonstrate a characteristic gut-signature or double-wall appearance, are contiguous with the bowel wall, and are typically extraluminal or mural rather than freely intraluminal. In contrast, the lesion in our patient was located within the bowel lumen, matched the obstructive transition point, had a thin capsule-like echogenic rim, and was associated with a subsequently confirmed exposure history. In this child, the sonographic finding led directly to more focused questioning of the family and clarification of the ingestion history. Since the examination in this case was not performed as point-of-care ultrasound (POCUS) by the primary team, our findings should be interpreted as supporting careful formal ultrasonographic evaluation rather than establishing reproducibility in less experienced POCUS settings. The potential role of POCUS would require further study and appropriate operator training.

Another important aspect of this case is the treatment strategy and patient selection. Earlier reports frequently described laparotomy and enterotomy for removal of obstructing beads (5,7). In contrast, Lei et al. reported that manual fragmentation with distal advancement into the colon may avoid enterotomy in selected patients (4). In our patient, several intraoperative factors supported a bowel-preserving approach: the foreign body was solitary, the bowel was viable, no perforation or ischemic change was present, no additional beads were found, and the obstructing bead was soft, compressible, and safely mobile toward the colon. These findings suggested that fragmentation and distal advancement could relieve the obstruction without bowel incision.

This strategy should not be applied indiscriminately. Contraindications may include suspected perforation, peritonitis, bowel necrosis or ischemia, severe bowel wall compromise, fixed impaction that cannot be advanced safely, multiple retained beads, uncertain foreign body composition, or inability to inspect the bowel adequately. In such situations, enterotomy, extraction, or bowel resection may be safer. In our patient, postoperative passage of large amounts of fragmented material, together with follow-up ultrasonography, confirmed complete resolution. Therefore, this case supports a practical diagnostic and therapeutic pathway for selected symptomatic patients: when a young child presents with unexplained bowel obstruction and radiography and CT are nondiagnostic, water bead ingestion should be specifically considered and ultrasonography should be performed carefully. If the foreign body is solitary, the bowel is viable, and safe manipulation is possible, laparoscopic fragmentation may represent a feasible bowel-preserving option.

Supplementary

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient’s legal guardians for publication of this case description and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.