An ileo–ileal idiopathic adult intussusception: diagnostic and therapeutic challenges from the emergency department: a case report

Abstract

Background

With this case report, we aim to draw attention to intussusception as a potential differential diagnosis in the emergency department for adults with diffuse abdominal pain and emphasize the importance of imaging studies in establishing a diagnosis and how to recognize the disease owing to possible serious and life-threatening consequences.

Case presentation

From the emergency department, intussusception was diagnosed in an adult, Caucasian, Croatian, male patient with a history of arterial hypertension and without a history of underlying intestinal disease. Family history was also without serious diseases. The 67-year-old Caucasian, Croatian, male patient presented to the emergency department with acute diffuse abdominal pain, nausea, acid regurgitation, and vomiting for the past 3 days. Laboratory results revealed leukocytosis, microcytosis, anisocytosis, and hypochromia. The serum C-reactive protein level was 181.9 mg/L. The native abdominal X-ray showed ileus of the small intestine. The patient was urgently referred for an abdominal computerized tomography scan, which showed dilated loops of the small intestine up to the transition zone in the ileum, where there was a target sign and kidney sign (intestinal loops within the lumen of another intestinal loop), indicating ileo–ileal intussusception. The described condition required urgent surgical intervention. A resection of the affected part of the small intestine (ileum) with an end-to-end anastomosis was performed, and a sample was sent for pathological examination. A histopathological diagnosis report corresponded to the referral clinical diagnosis: K56.2 Intussusception and volvulus of the ileum. The patient recovered successfully and was discharged for home care after several days.

Conclusion

Although intussusception occurs in children in 95% of cases, it is important to consider intussusception in adults as a life-threatening condition. In our case, the adult, Caucasian, male patient presented to the emergency department with diffuse abdominal pain, accompanied by nausea and vomiting. Imaging confirmed a serious condition: in this case, an abdominal computerized tomography scan verified small bowel dilatation with the characteristic target sign and kidney sign (bowel loops within the lumen of another bowel loop), which radiomorphologically confirms ileo–ileal intussusception. Surgical therapy was indicated. Thanks to the prompt and timely intervention of the emergency department physician as well as timely radiological diagnostics, the potentially threatening condition presented by our patient was quickly diagnosed, and the patient was successfully treated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13256-025-05563-x.

Introduction

With this case report, we aim to draw attention to intussusception as a potential differential diagnosis in the emergency department for adults with diffuse abdominal pain and emphasize the importance of imaging studies in establishing a diagnosis owing to possible serious consequences.

Intussusception is a medical term for a condition in which the proximal segment of the intestine (intussusceptum) invaginates into the lumen of the distal segment of the intestine (intussuscipiens) (Fig. 1). Retrograde intussusception, involving the invagination of the distal segment of the intestine into the proximal segment, occurs rarely [1, 2].

Fig. 1.

Intussusception as an invagination of the proximal part of the intestine into the distal part [taken from https://commons.wikimedia.org/wiki/File:Intussusception.svg. Creative Commons Attribution-Share Alike 3.0 Unported license. Author: Olek Remesz (wiki-pl: Orem, commons: Orem)]

Intussusception is an urgent condition that leads to obstruction of intestinal content passage, and if the intestine does not return to its normal position, it can stop the blood flow through the affected part of the intestine, leading to ischemia of the affected part within a few hours and ultimately causing the death of the affected part of the intestine [3].

In addition to ischemia, perforation of the affected part of the intestine or infection may occur. This situation requires urgent medical attention, and it is typically treated surgically.

Intussusception usually develops in children (95% of invaginations) between ages of 6 months and 3 years, being the leading cause of intestinal obstruction. The most common intussusception in childhood is ileocolic intussusception. At that age, in more than 90% of patients, there is no pathological substrate of the intestinal wall that is the cause of intussusception, and it is of unknown cause. However, it is believed that intussusception may occur more often in children who have a family history of gastrointestinal disorders [4, 5].

In children, the symptoms are nonspecific, as in adults, with the most common symptom being a sudden, loud cry. This is caused by sudden, intense abdominal pain in an otherwise healthy child [6].

Other symptoms include vomiting, bloody stools, fever, lethargy, bile vomiting, diarrhea, sweating, dehydration, and swollen abdomen. If left untreated, it can cause infection or even death [7].

Imaging plays a crucial role in diagnosis, primarily through ultrasound in the case of children. In the case of children, a treatment option to consider is a water-soluble contrast or air enema, and if there is perforation, urgent surgical intervention is chosen [8].

In adults, intussusception accounts for 5% of all obstructions, and usually its starting point is a well-defined pathological change in as many as 70–90% of cases, among which, in most cases, the cause is a neoplastic or nonneoplastic change in the intestinal wall (neoplasm, polyp, hematoma, diverticulum, duplication, or lymphoma), while in the remaining 15–25% of patients with a known cause of intussusception, the cause is intestinal adhesions or postoperative complications [9–11].

In addition to the mentioned causes, in patients with a pathological substrate of the intestinal wall, the possibility of developing intussusception has been correlated with frequent viral infections, parasites, appendicitis, celiac disease, cystic fibrosis, and Crohn’s disease [12, 13].

In this case, we describe an idiopathic ileo–ileal intussusception in an adult, Croatian, Caucasian male, with air–fluid levels shown on X-ray and a visible double wall (bowel within bowel) on abdominal computerized tomography (CT), along with mild haziness of the surrounding fatty tissue. The condition presented with abdominal pain, fever, and nausea.

Early recognition and diagnosis of intussusception are important for the best possible outcome for the patient, while good cooperation between emergency medicine specialists, clinical radiologists, abdominal surgeons, gastroenterologists, good clinical examination, and laboratory findings is essential.

The importance of imaging is crucial, and in adults, preference is given to computerized tomography.

The treatment method is urgent surgical intervention [14–16].

Case presentation

A 67-year-old Caucasian, Croatian, adult male from Zagreb, with a history of arterial hypertension, presented to the emergency department with diffuse abdominal pain, accompanied by nausea. He had vomited several times, expelling gastric contents, along with acid regurgitation. The pain had been ongoing for the past 3 days, but in the last few hours before coming to the emergency department, it worsened and spread to the epigastric region. Two days ago, he had a mild fever, reaching 37.6 °C, but was afebrile on the other days. He denied any chest pain or difficulty breathing. He had vomited gastric contents several times after meals.

His medical history included only arterial hypertension for the past 15 years, with no associated intestinal diseases. There was no history of gastrointestinal illnesses in the family.

In terms of functions and habits, his current appetite was diminished, and his last bowel movement was 2 days ago without any pathological findings. Urination was normal, he does not smoke, and he does not consume alcohol.

The patient was referred for an abdominal X-ray. The X-ray of the abdomen in the left lateral decubitus position showed prominently shaped loops of the small intestine with air–fluid levels—indicative of dilated loops of the small intestine, suggestive of ileus (Fig. 2).

Fig. 2.

From the hospital archives: native abdominal X-ray taken while lying on the left side

Blood tests were taken from the patient. The laboratory findings were as follows: white blood cells (WBC) 16.4 × 10⁹/L, mean corpuscular volume (MCV) 79.1 fL, mean corpuscular hemoglobin (MCH) 25.6 pg, red cell distribution width (RDW) 16.1%, absolute neutrophil count (ANC)% 85.90%, lymphocytes 2.70%, monocytes 11.20%, ANC 14.10 × 10⁹/L, lymphocytes 0.40 × 10⁹/L, monocytes 1.80 × 10⁹/L, microcytosis/hypochromia/anisocytosis, glucose 10.1 mmol/L, urea 10.7 mmol/L, creatinine 110 µmol/L, Na 131 mmol/L, alkaline phosphatase (ALP) 58 U/L, lipase 7 U/L, C-reactive protein (CRP) 181.9 mg/L, high-sensitivity cardiac tropinin I (hsTnI) 68.2 ng/L.

Following the described dilated intestinal loops with air–fluid levels and the obtained laboratory findings showing creatinine levels at the upper limit of physiological values, in quick collaboration between the attending physician in the emergency department and the on-call radiologist, an emergency CT scan of the abdomen and pelvis was indicated.

The emergency multislice CT scan of the abdomen and pelvis, both native and post-contrast in the portal–venous phase, revealed ileus of the duodenum, jejunum, and proximal half of the ileum with luminal widths up to 47 mm on axial sections. The ileum showed thickened walls up to 12 mm, with a transition zone of the ileum showing a target sign on the coronal section, indicating a bowel loop located within the lumen of another bowel loop/intussusception and, on the axial section, a visible kidney sign as radiomorphological confirmation of the diagnosis. Free fluid was observed interintestinally, paracolically, and in the small pelvis (Figs. 3a, b and 4a, b).

Fig. 3.

A From the hospital archives: view of intussusception on the performed computerized tomography scan in an axial section. B From the hospital archives: view of intussusception on the performed computerized tomography scan in an axial section (kidney sign)

Fig. 4.

A From the hospital archives: view of intussusception on the performed computerized tomography scan in the sagittal section (target sign). B From the hospital archives: view of intussusception on the performed computerized tomography scan in the coronal section (target sign)

The parenchymal organs appeared within physiological limits on the CT examination of the abdomen and pelvis. The abdominal aorta was appropriately calibrated and opacified.

A nasogastric tube was inserted.

Laboratory findings showed leukocytosis, microcytosis, anisocytosis, and hypochromia. The serum CRP value was 181.9 mg/L.

The urine analysis findings were normal.

An emergency surgery was performed next: resection of the ileal segment with end-to-end anastomosis (medial laparotomy). Exploration revealed a rotated loop of the ileum with visible intussusception. The described loop was gangrenous, so it was resected, and an end-to-end anastomosis (TT anastomosis) was performed. With abdominal cavity lavage, a drain was placed in the pelvic cavity and brought out through the right lower quadrant (RLQ).

The postoperative course went well with the following histopathological findings: The material was an 18-cm-long section of the small intestine with intussusception of the wall of the small intestine, which was gangrenous, dark brown to black in color, partly thinned, having a partly edematous wall and the lumen filled with bloody contents. There were greenish deposits on the serosa. Histologically, necrosis of all layers of the intestinal wall was visible, along with areas of extravasation of erythrocytes and accumulations of granulocytes and purulent bodies that spread into the underlying fatty tissue.

The findings corresponded to the referred clinical diagnosis: K56.2 Intussusception and volvulus of the ileum.

The patient was monitored after the surgical procedure and subjectively felt well.

The medical history and follow-up clinical examination revealed normal appetite, regular bowel movements, and vital signs appropriate for the patient’s age.

On abdominal examination, the abdomen was soft and nontender upon palpation, and the scar appeared normal.

A follow-up X-ray of the abdomen showed normal findings.

The patient was discharged from the hospital in good condition after a few days and advised to continue care at home. Further follow-up was scheduled with the primary care physician.

Discussion

Intussusception is a rare cause of intestinal obstruction in adults, occurring in children in more than 95% of cases. The exact mechanism of its occurrence is unknown, but it is believed that any lesion in the intestinal wall or irritation within the lumen that disrupts normal peristalsis can trigger the development of intussusception [4, 7].

The interplay of food and the peristalsis of the intestinal wall leads to constriction above the point of origin and relaxation below, resulting in telescopic invagination of the proximal into the distal intestine. As the mesentery is drawn in, compromise of venous flow occurs, leading to edema formation and further restriction of blood flow.

Ultimately, arterial flow obstruction occurs, leading to ischemia and necrosis of the wall of the affected part of the intestine [2, 17].

The clinical presentation is nonspecific, making it challenging to diagnose. Abdominal pain, nausea, vomiting, and bloody stools are the most common symptoms in adults.

The role of good and timely radiological diagnostics is crucial.

Native abdominal X-ray is often the initial diagnostic method that can reveal signs of intestinal obstruction, such as the presence of pathological air–fluid levels or pathological distension of bowel loops (small intestine > 3 cm in luminal width, cecum > 6 cm, rest of the colon > 9 cm) [17].

Several imaging methods can aid in establishing the diagnosis: barium meal examination, abdominal ultrasound, and computed tomography. Barium meal examination and abdominal ultrasound are more prevalent in diagnosing acute pain in children, while in adults, the choice of imaging method depends on the clinical question, age, patient’s condition, and renal function, and in this case, computed tomography was indicated.

Abdominal CT examination is the most useful method for diagnosing intussusception, being superior to other contrast studies, ultrasound, and endoscopic examinations. Classic findings on CT examination are the target sign and kidney sign.

A trilayered image is observed with the lumen and wall of the intussusceptum as the inner layer, mesenteric fat as the central layer, and the intussuscipiens as the outer layer. CT is excellent for visualizing the location and cause of intestinal obstruction, as well as for diagnosing possible ischemia of the intestine [18].

The final diagnosis is made intraoperatively and confirmed by pathological examination.

Surgical intervention is necessary in cases of intussusception in adults. The surgical technique and the extent of resection depend on the length of the affected intestine, the causes of obstruction (benign or malignant), and the patient’s age [15].

In this case, resection of the ileal segment was preformed with end-to-end anastomosis, with exploration of the rotated gangrenous loop of the ileum and visible intussusception.

With timely radiological diagnostics and surgical intervention, the patient’s problem (intussusception) was successfully diagnosed and treated.

Conclusion

Intussusception is a rare cause of acute abdomen in adults with nonspecific symptoms. Our patient, 67-year-old, Caucasian, Croatian, male adult with history of arterial hypertension, presented to the emergency department with diffuse abdominal pain, nausea, vomiting, and fever.

On the basis of the clinical presentation and X-ray findings, the patient’s serious condition was recognized, and an abdominal CT scan was performed for further evaluation.

Abdominal CT examination is the most useful method for diagnosing intussusception, being superior to other contrast studies, ultrasound, and endoscopic examinations.

The classic findings on the CT scan are the target sign and the kidney sign, both demonstrated in this case, along with mild haziness of the surrounding fatty tissue.

Therapy in such cases almost always involves classical or laparoscopic surgical intervention. The surgical technique and the extent of resection depend on the length of the affected intestine, the causes of obstruction (benign or malignant), and the patient’s age. In the presented case, resection of the ileal segment with end-to-end anastomosis was performed.

Author contributions

All authors have contributed to this manuscript in terms of planning and design, writing and editing various drafts of the manuscript, and have read and approved the final version.

Funding

Not applicable.

Availability of data and materials

The databases used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

Written informed consent was obtained from the hospital ethics commitee from Clinical Hospital Dubrava to use patients images stored in hospital database.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests

The authors have no relevant financial interests and no potential conflicts of interest to disclose.