Intussusception: the Good, the Bad and the Ugly

Here is the case:

A healthy, 6 year old boy, Joey, presents to the ED for the second time in a week with abdominal pain.

He was initially seen 3 days earlier with a history of intermittent central / lower abdo pain that was not really progressive until it became worse, he vomited and his Dad brought him into the ED at 01:00 in the morning. (vomiting seems to be the trigger for many presentations!)

At the time Joey had normal observations.  His pain settled with oral ibuprofen and his abdominal exam was recorded as “NAD”, no peritonism or distension.  He was discharged with the diagnosis of “probable mesenteric adenitis” and asked to return if the pain became persistent or he developed fevers.

Today Joey represents with very similar symptoms – pain that is on and off every few hours and a crescendo of pain leading to a vomit just before triage. No fevers, diarrhea or other new symptoms… The family does not report any recent viral URTI or other antecedent illness but… it is now day 7 of pain.  They are keen for investigation.

So, being a sononerd, you need no further invitation to apply the probe and go hunting for Joey’s appendix or whatever else may be the culprit…

Here is the view of the RLQ:

Right lower quadrant / transverse view

No appendix in sight, but as you follow the pain you do notice a series of small, hypoechoic, benign looking mesenteric lymph nodes.  Maybe that is the diagnosis? However, you keep scanning….

Joey indicates that the main pain is in the left lower quadrant so you look over there…

Left lower quadrant – longitudinal view of lesion

What is this?  What are we seeing on these 2 views at 90 degrees to one another through the same structure?

This is intussusception.  And being located in the LLQ it is most likely an ileo-ileal or small bowel intussusception.

Keen to teach, you grab a few nearby residents and ask them to scan Joey… but alas, they cannot locate the lesion.  Assuming they are looking in the wrong spot you look again… and it is gone!  As is Joey’s pain.  He suddenly looks much brighter and his parents are looking at you as if to ask : “do you know what you are doing with that thing?”

Fortunately, you are a disciplined sononerd who always labels and saves the images you take… you go back and review – yes, it is a clear intussusception – a textbook example.

So, what to do?  We need to know what’s the plan for Joey.  He looks great now, he has just gulped down a bottle of juice and a banana…. You decide to call the on-call paediatrician.  Here is how the conversations goes:

ED: Hi , I have a healthy 6 yo boy who has represented with now 7 days of pain. He appears well …. But he has an intussusception on ultrasound..

Paeds: What… an intussusception?

ED: yeah, well he did, it has gone now…

Paeds: Doctor, an intussusception is a surgical emergency… you need to call the surgeons…

ED: yes, I know.. It’s just that…he looks well and the intussusception has gone away…

Paeds: Umm, gone away?  I don’t trust your ultrasound… just get a plain film and call the surgeons.

ED: Sigh…

*you hang up*   Knowing that a plain abdominal X-ray is about as useful as D-dimer in this instance…

So. Let’s pause the case there.  

Is the Paediatrician correct – is intussusception a surgical emergency?

Can Intussusception magically disappear in 15 minutes?

What should be done with Joey?

Let us take a look at the history of this disease and see what has changed in recent years.  It turns out that the advent of ultrasound on the ED floor has changed the way we view this disease, the care delivered and outcomes for our patients.

Intussusception was first described in 1674 by Barbette in Amsterdam.  It was recognised as a serious surgical condition – usually diagnosed post-mortem – by the classic English surgical fraternity in the 1700s.  At this time an intussusception was diagnosed clinically, there were no imaging techniques available.  The mortality was almost universal aside from a few lucky surgical survivors.

The real change in intussusception came in 1876 when Dr Harald Hirschprung (yes, the same Hirschprung) described the first ever hydrostatic enema to reduce an intussusception non-operatively. By 1905 he had performed more than 100 enema-reductions and 70% had survived.

The enema-reduction technique spread all over the globe and by the early 1900s was becoming the standard of care.  The introduction of barium contrast to aid diagnosis in the 1940s improved the technique.  Surgery was reserved for children where the enema failed or due to late presentation and perforation it was contraindicated.  By 1970 the mortality had reduced to just 6%.  Intussusception remained a crucial diagnosis to make early, but for the most part was manageable if caught.

The 1980s saw the change to air-insufflation techniques on the basis of a massive case series of nearly 7,000 patients out of China by Dr Guo.  The Chinese achieved an amazing 95% success rate with the air enema approach.

The 1980s also saw the introduction of ultrasound to both diagnose and guide reduction of intussusception.  During this period the big gains were to be made in identifying the 10% of children who suffered early recurrence of their intussusceptions – usually resulting from the presence of pathological lead points within the bowel wall.

In the last 30 years ultrasound has become the modality of choice for diagnosing intussusception in children.  Sonography has diagnostic sensitivity in the high 90s and is also very specific – at least 95%.  The advent of point-of-care ultrasound in the Emergency Departments of the world means that we are scanning more and more children with this sensitive technique – and of course diagnosing a lot more.  It has become more common to see intussusception whilst scanning patients for unrelated symptoms. So how do we know who has an intussusception that needs treatment now vs. those who can carry on with life?

There is an inevitability of any medical diagnostic technology – the better the test gets, the more murky the results become.  That is to say that we can diagnose this disease more easily – but we now have included a spectrum of disease that would have previously remained sub-clinical.  Yes, there are intussusceptions that just slide right by and never cause any trouble.

Hence, the cognitive dissonance we feel when we pick up the probe to make this crucial, time-critical and serious surgical diagnosis…. In a well, happy child.  We are now at that point in history where we need to sort the goats from the sheep and know what are the good, the bad and the ugly types of intussusception.

The evidence on this has expanded in the last few years with the emergence of what looks like two very different diseases processes:

  1. “ileo-colic intussusception” – the one we all fear 
  2. “small bowel intussusception” – a benign and usually transient, self-limiting phenomenon.

Fortunately, ultrasound is very useful in differentiating these two processes.  There are a series of sonographic features that are quite reliable in sorting this all out!

The following is a table I have compiled from the literature published in the last 5 years on this topic. [References below]

Feature Ileo-colic intussusception Small bowel intussusception suggested cut off
Age 6 -13 months 3 – 7 years the ICI “nasty” ones occur in the traditional age – infancy
Sex same same Boys get more intussusception than girls
Vomiting 43% 74% Hard to use as cut off – not specific
Bloody stool 44% 9% Blood seems to predict badness ? ischemia
Abdo pain 95% 45%  
US features      
– wall thickness > 4 mm 2-3 mm  
– diameter of lesion 27 mm 17 mm (11-23) anything over 25 mm likley ICI
– core:wall thickness ratio 1.9 0.7 a larger core / trapped loop = not good
– length of intussusceptum 53 mm 27mm anything over 30 mm likley ICI
-lymph nodes within lesion 85 – 90% 1 – 14% Seems like a good discriminator!
– presence of a patholgical ead point common never Not always seen but should prompt concern
– normal ileocaecal valve image 0% 85% Best to show this is an ICI, reassuring if normal
– presence of intralesion fluid collection more likely if PLP rare A sign if ischemia / obstruction – need for intervention
– location R side / ascending colon Left / other  
– normal mural vascular flow ? 95% reassuring / good prognosis
– peristalsis present ? Common a sign of normal function and flow is reassuring
Spontaneous resolution 3 – 17% 95 – 100%  
Persistent obstruction after 6 hrs 99% <1% 6 hours in Wang was the time of intervention

So Joey almost certainly had a transient small bowel intussusception. This is the “Good” form of intussusception. The images have most of the features consistent with a benign small bowel lesion with a high chance of spontaneous resolution. How should we manage kids like Joey?

I think that we should observe and rescan in a serial fashion over 12 – 24 hours. The idea is to detect recurrence and rescanning makes it more likley to detect a pathological lead point which would change our management. However, there are also the bad and the ugly forms of this disease. These remain critical diagnoses to make in a timely manner. We need to be vigilant and know when we are dealing with these more severe forms of intussusception.
there have been a series of case series published in the last few years that give us some numbers to help split the good from the bad and ugly. There is a lot of heterogeneity in the measuring and scanning strategies in these articles. However, I can see patterns emerging in the tables and supplements. If I were going to choose the sonographic features that we need to look for to identify the more nasty intussusception case then I would go with:


  1. small infant (< 12 months) or adults
  2. total lesion diameter > 2.5 cm (an inch)
  3. intussuceptum length > 3 cm
  4. A thick fatty core (ie. a high core:wall ratio > 1:1 )
  5. Absence or blood flow or active peristalsis
  6. involving the ileo-caecal valve
  7. presence of intralesional lymph nodes or another pathologic lead point
    • eg. bowel lesion: HSP, polyp, duplication cyst, Meckel’s
  8. Free fluid within the lesion or peritoneum

Like any disease intussusception exists over a spectrum. Imaging can help us diagnose this but we need to remain good clinicians, we need to understand what we are seeing. The beauty of bedside scanning is that we can integrate this data into the clinical picture as we scan. So now you know – look for the features above and make the call early – who needs an enema, and who needs to be watched and reviewed?


Ultrasonographic Diagnosis of Intussusception in Children: A Systematic Review and Meta-Analysis
Xing-Zhao Li, Journ Ultrasound Med 2020; 9999:1–8

Can intussusceptions of small bowel and colon be transient? A prospective study
Qi Wang European Journal of Pediatrics Aug 2019

Intussusception Then and Now: A Historical Vignette. Jay L Grosfeld. Journ Amer Coll Surgery Dec 2005

Results of Air Pressure Enema Reduction of Intussusception: 6,396 Cases in 13 Years
Jing-zhen Guo, Journal of Pediatric Surgery, Vol 2 1, No 12 (December), 1986: pp 120 1- 1203

Spontaneous reduction of intussusception: clinical spectrum, management
and outcome. Kornecki. Pediatr Radiol (2000) 30: 58±63

Intussusception: past, present and future Emily A. Edwards Pediatr Radiol (2017) 47:1101–1108

ISHAN GOEL. Ultrasound in Med. & Biol., Vol. 46, No. 3, pp. 589597, 2020

Accurately distinguishing pediatric ileocolic intussusception from small-bowel intussusception using ultrasonography. Min Zhang, Journal of Pediatric Surgery,

Point-of-care ultrasound diagnosis of small bowel-small bowel vs
ileocolic intussusception Brian L. Park. American Journal of Emergency Medicine 37 (2019) 1746–1750

Intussusception- University of California, San Diego, School of Medicine, and the University of California Medical Center, San Diego (Specialty Conference). M, Buchta R, Raszynski A, et al: West J Med 130:35-42, Jan 1979

Diagnostic Accuracy of Point-of-Care Ultrasound for Intussusception in Children Presenting to the Emergency Department: A Systematic Review and Meta-analysis
Margaret Lin-Martore. Western Journal of Emergency Medicine 1008 Volume 21, no. 4: July 2020

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