A 6 year old boy presents with lower abdominal pain and vomiting. He has had intermittent pain for a week thought to be due to mesenteric adenitis.

View 1: Longitudinal view taken at the left lower quadrant
View 2: Transverse view taken at the left lower quadrant

Describe and interpret these scans

Video 1 & 2: Longitudinal and transverse views taken at the left lower quadrant, at the site of tenderness.

A small bowel intussusception is seen. The bowel remains active; the length of the intussusception is short (2cm), and the diameter small (2cm); there is no echogenic core, and no obvious pathological lead point is seen.

This is typical of a small bowel intussusception (small bowel into small bowel). These are commonly benign, and resolve spontaneously without need for intervention. Conservative management with observation in the first instance if the patient is relatively well is reasonable.

Asymptomatic short segments of intussusception have been reported as incidental findings in imaging studies done for other indications.

Slide over to reveal: Small bowel intussusception with and without labels.


This is a short segment of small bowel intussusception with active peristalsis seen.

Intussusception involving the ileo-caecal valve (terminal ileum into caecum) or a pathologic lead point is a surgical emergency. Transient small bowel intussusception (small bowel into small bowel) is a relatively common US finding and tends to be self resolving if there are no concerning features present.

These are the features we look for that predict the need for intervention:

  • Infant (< 12 months) or adults
  • Total lesion diameter > 2.5 cm
  • Intussusceptum length > 3 cm (the inside bit)
  • A thick fatty core (a high core:wall ratio >1:1)
  • Absence or blood flow or active peristalsis
  • Involvement of the ileo-caecal valve
  • A pathological lead point such as a lymph node, Henoch-Schönlein purpura polyp, duplication cyst, or Meckel’s diverticulum



Cite this article as: Casey Parker and James Rippey, "Ultrasound Case 109," In: LITFL - Life in the FastLane, Accessed on November 28, 2022,


GP working in Broome in the NW of Western Australia. I work as a hospital DMO (District Medical Officer) doing Emergency, Anaesthestics, some Obstetrics and a lot of miscellaneous primary care | @broomedocs | BroomeDocs |

An Emergency physician based in Perth, Western Australia. Professionally my passion lies in integrating advanced diagnostic and procedural ultrasound into clinical assessment and management of the undifferentiated patient. Sharing hard fought knowledge with innovative educational techniques to ensure knowledge translation and dissemination is my goal. Family, wild coastlines, native forests, and tinkering in the shed fills the rest of my contented time. | SonoCPDUltrasound library | Top 100 | @thesonocave |

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