https://orcid.org/0009-0001-1647-7319
Abstract
Adult intussusception is a rare cause of intestinal obstruction and is typically associated with an underlying pathological lead point. Postoperative intussusception without an identifiable lesion is particularly uncommon and may present diagnostic and therapeutic challenges. We report the case of a 44-year-old woman who developed epigastric pain, nausea, and vomiting on postoperative Day 3 following small bowel resection and enterouterine fistula excision for adhesive bowel obstruction. Contrast-enhanced abdominal computed tomography demonstrated a 20-cm ileoileal intussusception with a characteristic bowel-within-bowel appearance and no identifiable lead point. Urgent surgical re-exploration confirmed ileoileal intussusception ~60 cm proximal to the previous anastomosis. The bowel was viable, and successful manual reduction with adhesiolysis was performed without resection. This case highlights the importance of considering postoperative intussusception in adults presenting with early postoperative bowel obstruction and supports bowel-preserving management in selected patients with viable bowel and no suspicious lesion.
Introduction
Intussusception is defined as the telescoping of a proximal segment of the intestine into an adjacent distal segment, potentially leading to bowel obstruction, ischemia, and perforation if untreated. While it represents a common cause of intestinal obstruction in children, adult intussusception is rare, accounting for ~1%–5% of adult small-bowel obstructions and about 5% of all cases of intussusception [1, 2].
Nearly 90% of adult intussusceptions are associated with an underlying pathologic lesion, most commonly polyps or neoplasms, that acts as a lead point. In contrast, postoperative intussusception in adults is uncommon and represents a rare surgical complication [3].
We report a rare case of early postoperative small-bowel intussusception in an adult woman following laparotomy for adhesive obstruction and enterouterine fistula resection, presenting with acute abdominal pain and radiologic concern for evolving ischemia without an identifiable lead point. Prompt re-exploration confirmed an ileoileal intussusception remote from the prior anastomosis, which was successfully managed with manual reduction and adhesiolysis.
Case presentation
A 44-year-old woman with no significant medical history and previous cesarean section complicated by uterine perforation, as well as open appendectomy, presented with epigastric pain, nausea, and vomiting. Imaging demonstrated partial small bowel obstruction. Due to the failure of conservative management, she underwent an urgent exploratory laparotomy. Dense intra-abdominal adhesions were released, a segment of ileum was resected with a side-to-side anastomosis, and an enterouterine fistula was excised.
On postoperative Day 3, she developed new epigastric pain associated with abdominal distension and an absence of flatus or bowel movements. She was hemodynamically stable. Laboratory tests showed a normal leukocyte count with elevated C-reactive protein. Arterial blood gases were normal.
Contrast-enhanced abdominal computed tomography (CT) revealed a long-segment ileoileal intussusception measuring ~20 cm (Fig. 1), demonstrating the characteristic “bowel-within-bowel” configuration with invaginated mesenteric fat and vessels. Mild wall thickening and mesenteric fat stranding were present. Oral contrast traversed the segment, suggesting partial patency. No pathological lead point, perforation, or pneumatosis was identified.
Selected axial (A) and coronal (B) images of the patient’s abdomen CT with IV and oral contrast demonstrate a segment of ileo-ileal intussusception associated with mild circumferential bowel wall thickening and adjacent mesenteric fat stranding (circles); internal invagination of mesenteric fat and vessels is noted, forming a crescent-shaped configuration around the compressed central lumen (arrows), which is surrounded by the two layers of the outer intussuscepted bowel, consistent with the classic “bowel-within-bowel” appearance; oral contrast is seen within the lumen of the intussuscepted segment, with contrast material appearing to extend distally into the large bowel, suggesting partial luminal patency.
Given persistent symptoms and imaging findings, urgent re-exploration was performed. An ileoileal intussusception was identified ~60 cm proximal to the previous anastomosis. The involved bowel was edematous but viable, without signs of ischemia. Manual reduction was successfully achieved (Fig. 2). No intraluminal or extraluminal lead point was identified. Inspection of the entire small bowel revealed a loop adherent near the prior anastomosis, which was released. The anastomosis was intact and patent.
Intraoperative exploration revealed an ileoileal intussusception characterized by invagination of the proximal ileal segment into the distal bowel.
After irrigation and confirmation of bowel viability, the abdomen was closed with drain placement. The postoperative course was uneventful. The patient resumed oral intake and normal bowel function and was discharged on postoperative Day 7. No recurrence or complications were noted during follow-up.
Discussion
While intussusception is the most common cause of bowel obstruction in children, it is rare in adults, accounting for ~5% of all intussusceptions and only 0.003%–0.02% of adult hospital admissions. Unlike childhood intussusception, which is idiopathic in nearly 90% of cases, adult intussusception is typically secondary to an identifiable pathological lead point, reported in 70%–90% of cases [4, 5].
Primary or idiopathic intussusception accounts for ~8%–20% of adult cases and is more frequently encountered in the small intestine. This invagination can cause luminal obstruction and compromise mesenteric perfusion, leading to edema, ischemia, or necrosis [6].
Adult intussusception may arise from benign, malignant, or idiopathic causes; common lead points include polyps, lipomas, inflammatory lesions, Meckel’s diverticulum, adhesions, or tumors [7].
Adult intussusception often presents with nonspecific symptoms such as abdominal pain, distension, nausea, vomiting, and altered bowel habits, which can delay diagnosis. Postoperative intussusception is rare in adults and may mimic ileus, complicating timely recognition and management [4]. In the present case, a 44-year-old woman developed postoperative ileoileal intussusception following small bowel resection for adhesive obstruction and enterouterine fistula. Consistent with the literature, the clinical presentation was nonspecific and initially indistinguishable from common postoperative entities such as ileus. As previously reported, this overlap frequently leads to delayed recognition.
Ultrasonography may show the “target” or “doughnut” sign on transverse view and the “pseudo-kidney” sign on longitudinal view [6].
A CT scan is the most sensitive imaging modality for confirming intussusception. Characteristic CT findings include a heterogeneous “target” or “sausage-shaped” soft-tissue mass with a layered appearance, often containing mesenteric vessels within the lumen. Moreover, CT may help differentiate intussusception with a lead point typically associated with bowel obstruction, wall edema, and loss of the normal layered pattern from transient or idiopathic forms without a lead point, potentially reducing unnecessary surgical interventions [6]. In our patient, contrast-enhanced CT was crucial in establishing the diagnosis, demonstrating a long-segment ileoileal intussusception with the classic “bowel-within-bowel” configuration and no evident lead point.
Adult intussusception often presents with nonspecific acute, subacute, or chronic symptoms, leading to delayed diagnosis, sometimes only during surgery. Because of the high likelihood of an underlying structural cause and the risk of malignancy, operative management is generally preferred in adults. Unlike pediatric cases, where intussusception is usually idiopathic and treated with nonoperative reduction, adult cases typically require surgical intervention. However, the role of intraoperative reduction before resection remains controversial due to concerns about tumor dissemination, perforation, and bowel ischemia [6].
When a benign etiology is confidently suspected, cautious reduction may be considered to preserve bowel length, particularly in small bowel intussusception caused by benign lesions. This bowel-preserving approach is especially relevant in conditions such as Peutz–Jeghers syndrome or postoperative intussusception, where reduction may be attempted if the bowel is viable [6].
Laparoscopic management has also been increasingly reported, allowing both diagnosis and definitive treatment with the benefits of minimally invasive surgery in selected patients [6].
Unlike most adult cases associated with a pathological lead point, no lesion was identified in our patient. The intussusception occurred ~60 cm proximal to the previous anastomosis, suggesting a postoperative functional or adhesional mechanism. As there was no ischemia or suspicious lesion, safe manual reduction was performed without bowel resection. This case highlights that bowel-preserving strategies may be appropriate in selected adults with viable bowel and no identifiable lead point. Postoperative ileoileal intussusception should therefore be considered in patients presenting with early postoperative bowel obstruction.
Conclusion
Adult intussusception is a rare and diagnostically challenging cause of bowel obstruction, particularly in the postoperative setting, where symptoms may mimic ileus or other common complications. Imaging, especially contrast-enhanced CT, plays a crucial role in timely diagnosis and in differentiating idiopathic or transient intussusception from cases associated with a pathological lead point. Management should be individualized: while formal resection is often recommended due to the risk of malignancy, viable bowel without a lead lesion can be safely managed with careful manual reduction, avoiding unnecessary bowel loss. This case highlights postoperative adhesional intussusception as an uncommon but important cause of early postoperative obstruction and underscores the value of prompt recognition, judicious surgical decision-making, and bowel-preserving strategies in selected adult patients.
Acknowledgements
The authors express their gratitude to the patient and their family for their great contribution.
Conflicts of interest
We declare that no conflict of interest could be perceived as prejudicing the impartiality of the research reported.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not for-profit sectors.
Data availability
The data used to support the findings of this study are included in the article.
Ethics approval
Our institution does not require ethical approval for reporting individual cases or case series.
Informed consent
Written informed consent was obtained from the patient’s family for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal if requested.
