Intussuception

Question 1

What is intussusception and where does it most commonly occur?

Answer 1

Intussusception is the invagination of one portion of the bowel into the lumen of an adjacent segment, most commonly occurring around the ileo-caecal region.

Question 2

Who is most commonly affected by intussusception?

Answer 2

Intussusception typically affects infants between 6-18 months old, with boys being affected twice as often as girls.

Question 3

Describe the clinical features of intussusception.

Answer 3

Features include intermittent, severe, crampy abdominal pain, inconsolable crying, the infant drawing knees up and turning pale during pain, vomiting, and a ‘red-currant jelly’ bloodstained stool as a late sign. A sausage-shaped mass may be palpable in the right upper quadrant.

Question 4

What is the preferred method of investigation for intussusception?

Answer 4

Ultrasound is the preferred investigation for intussusception, often revealing a target-like mass.

Question 5

What are the primary management strategies for intussusception?

Answer 5

Management generally involves non-surgical reduction via air insufflation under radiological control, which is considered first-line treatment. If this fails, or if signs of peritonitis are present, surgical intervention is necessary.

Question 6

An 18-month-old girl is brought to A&E by her father. She has vomited several times over the last 24 hours. On examination, she is irritable and has a distended abdomen with tinkling bowel sounds. Which investigation is most likely to reveal the underlying diagnosis?

Abdominal ultrasound
Abdominal X-ray
Endoscopy
Stool culture
Faecal calprotectin

Answer 6

1. Abdominal ultrasound

Intussusception is a condition that mainly occurs in young children (<2 years) and is characterised by telescoping of a section of the intestines. It most commonly occurs at the ileocaecal junction. Patients can present with features of bowel obstruction (vomiting, absolute constipation, abdominal distention) or they may describe an intermittent course where the child becomes irritable, pale and draws their legs up to their chest. Blood-stained ‘redcurrant jelly stools’ are classically associated with intussusception, however, this is a late sign that requires urgent intervention. Intussusception may develop after a non-specific febrile illness. This is thought to be due to enlarged Peyer’s patches acting as a lead point for the intussusception. An abdominal ultrasound scan focusing on the
Refer for MRI of affected arm
Take bloods for coagulation screen
Urgently refer to paediatric orthopaedics
affected part of the intestines may reveal ‘target sign’. An abdominal X-ray may be useful to demonstrate bowel obstruction, however, it would not necessarily reveal the underlying diagnosis. Intussusception is usually treated using rectal air insufflation with fluoroscopy guidance. This involves pumping air into the intestines to reverse the intussusception. Occasionally, if this is unsuccessful, a surgical approach will be necessary. Patients should also be nil-by-mouth, have a nasogastric tube inserted and given adequate fluid resuscitation. Recurrent intussusception may warrant further investigation to search for a pathological lead point (e.g. Meckel’s diverticulum).

Question 7

A one-year old girl presents to the Emergency department with intermittent abdominal pain. Her father explains that during these episodes the child becomes irritable, pale, and draws her legs up towards her abdomen. There has been no vomiting, but the child has refused feeds for two days. The abdomen is soft, but there is a palpable, sausage shaped mass in the right flank.

Given the likely diagnosis, what is the first line management after resuscitation?

Laparoscopic correction

Watch and wait

Laparotomy

Hydrostatic enema

Air enema

Answer 7

Air enema

The diagnosis is intussusception. For patients without peritonism, this is the first line treatment, and is successful in 75%. Air is used to create pressure within the intestine to resolve the obstruction

Question 8

SUMMARY of intussaception - quesmed

Answer 8

SUMMARY
Intussusception is a medical condition that involves the invagination of a proximal segment of the bowel into a distal one, often the ileum passing into the caecum. Predominantly affecting infants between 3 months and 2 years old, it presents with severe colicky pain, lethargy, refusal of feeds, vomiting, passage of blood-stained mucus resembling redcurrant jelly, abdominal distension, and a potentially palpable mass in the abdomen. An ultrasound will typically show a ‘target’ sign and may also reveal complications such as free-abdominal air or gangrene. Management depends on the patient’s stability, with rectal air insufflation or contrast enema as first-line treatments, and operative reduction reserved for more severe cases or unsuccessful initial management.

Question 9

Definition of Intussucapetion

Answer 9

DEFINITION
Intussusception refers to the invagination (telescoping) of a segment of the proximal bowel into a distal bowel segment. The most common scenario is the ileum passing into the caecum through the ileocaecal valve.

Question 10

Epidemiology of Intussuception

Answer 10

EPIDEMIOLOGY
Intussusception primarily occurs in infants, with the peak incidence age between 3 months and 2 years.

Question 11

Aetiology of intussuception

Answer 11

AETIOLOGY
The precise aetiology of intussusception remains uncertain in many cases, with the condition frequently being idiopathic. Nonetheless, several factors have been identified that increase the risk of developing this condition:

Viral infections: Recent or concurrent viral infections, particularly those involving the gastrointestinal tract, may predispose a child to intussusception. This is thought to occur due to the enlargement of Peyer’s patches in the terminal ileum following an infection, which can act as a lead point for intussusception.
Lymphoid hyperplasia: Similar to viral infections, conditions leading to lymphoid hyperplasia can trigger intussusception. Diseases such as lymphomas or infections that cause lymphoid hyperplasia can serve as a ‘lead point’ for the telescoping of the bowel.
Meckel’s diverticulum: This congenital abnormality, a remnant of the omphalomesenteric duct, can serve as a ‘lead point’ for intussusception. It is the most common congenital anomaly of the gastrointestinal tract and is present in approximately 2% of the population.
Polyps: Intestinal polyps, particularly those of a larger size, can act as a ‘lead point’ for the invagination process in intussusception. These are rare in children but can be seen in certain syndromes such as Peutz-Jeghers syndrome and familial adenomatous polyposis.
Cystic fibrosis: Patients with cystic fibrosis have increased viscosity of intestinal secretions, which can potentially cause a blockage that serves as a ‘lead point’ for intussusception.
Henoch-Schönlein purpura: This vasculitic condition can cause inflammation and swelling in the bowel wall, potentially leading to a ‘lead point’ for intussusception.
Vaccination: Some studies have reported an increased risk of intussuception following rotavirus vaccination, usually within a week after the first or second dose. Despite this, the benefits of the vaccine far outweight this small associated risk.
It should be noted that while these factors can increase the risk of intussusception, many cases occur in the absence of any identifiable predisposing condition.

Question 12

Signs and symptoms of intussuception

Answer 12

SIGNS AND SYMPTOMS
The presentation of intussusception includes:
Paroxysmal, severe colicky pain, often causing the child to draw up his legs
Lethargy and decreased activity between pain episodes
Refusal of feeds
Vomiting, which may be bile-stained depending on the location of the intussusception
Passage of a ‘redcurrant jelly’ stool, which consists of blood-stained mucus
Abdominal distension
Palpation may reveal a sausage-shaped mass in the abdomen

Question 13

Differential diagnosis of intusseption

Answer 13

DIFFERENTIAL DIAGNOSIS
Several conditions can mimic the symptoms of intussusception:
Gastroenteritis: Presents with diarrhoea, vomiting, and abdominal pain, but lacks the characteristic ‘redcurrant jelly’ stool and palpable abdominal mass.
Appendicitis: Characterised by lower right abdominal pain, vomiting, and fever, but does not involve the passage of ‘redcurrant jelly’ stools.
Volvulus: Presents with severe abdominal pain, vomiting, and possibly a distended abdomen, but lacks the ‘redcurrant jelly’ stools and specific mass.
Meckel’s diverticulum: Can present with painless rectal bleeding and occasionally abdominal pain, but lacks the typical colicky pain and lethargy seen in intussusception.

Question 14

Investigation for intussuception

Answer 14

INVESTIGATIONS
Abdominal ultrasound is the primary investigation method for intussusception. The classic ‘target’ sign, represented by concentric echogenic and hypoechogenic bands, is often seen. Ultrasound can also reveal complications such as free abdominal air or the presence of gangrene.

Target sign seen on ultrasound scan.
Target sign seen on ultrasound scan.

Question 15

Management of intussuception

Answer 15

MANAGEMENT
The management of intussusception varies based on the child’s stability and the presence of complications:
Initial management typically involves rectal air insufflation or a contrast enema, but these should only be performed if the child is stable.
Operative reduction is indicated in the following scenarios:
Non-operative management has failed.
The child presents with peritonitis or perforation.
The child is haemodynamically unstable.

Question 16

A 10-month old baby boy develops rapid onset abdominal pain. His mother tells you he has been off his food and not his usual temperament for 3 days prior to this. He is producing regular wet nappies and there are no rashes. He has not vomited however this morning he passed one episode of redcurrent jelly stools. On examination he looks pale and his abdomen there is a sausage shaped mass in the right upper quadrant and the boy draws ups his legs and screams uncontrollably on palpation.

What is the most likely diagnosis?

Pyloric stenosis

Mesenteric adenitis

Viral gastroenteritis

Intussusception

Crohn’s disease

Answer 16

Intussusception
Intussusception should be considered in young infants or toddlers with screaming attacks. It occurs when one portion of bowel prolapses into the lumen of the adjacent bowel (‘telescoping’). It may present with redcurrent jelly stools and a sausage shaped mass on examination, and there may be a history of being unwell 1-3 days prior to presentation. It is most common in 3 months - 12-month-old children and 75% are ileocaecal in location. If the child is relatively well, pneumatic reduction under fluoroscopic guidance can be attempted. If the child is unwell or perforation is suspected laparotomy is the treatment of choice

Question 17

A 10-month-old male infant is brought to the Emergency Department with sudden onset of inconsolable crying episodes and who is drawing up the knees to their chest during these episodes. The parents mention he seems to be normal in between the episodes. He is refusing feeds and passing redcurrant-like jelly stools since yesterday.

On examination, a palpable ‘sausage shaped’ abdominal mass can be found in the right upper quadrant.

Given the history, what is the single most appropriate investigation to diagnose the condition?

CT scan

Abdominal X-ray

Urea and electrolytes (U&Es)

Abdominal ultrasound

Stool microscopy for ova, cysts and parasites (OC&P)

Answer 17

Abdominal ultrasound
Intussusception is the movement or ‘telescoping’ of one part of the bowel into another. The proximal bowel segment is referred to as the intussuceptum, while the distal segment is known as intussucipiens. Ultrasound is the preferred method of diagnosis, as it has a high sensitivity in comparison and can help exclude alternative diagnoses. It shows a characteristic doughnut/target sign (concentric alternating echogenic mucosal and muscularis bands and hypoechoic submucosal bands).

Question 18

An 8-month-old male infant who has previously been well presents with difficulty feeding to the GP. They have been having episodes of leg flexing after eating, there is irritability and lethargy after meals. There is redcurrant jelly stool on examination of the nappy.

There is no past medical history and no concerns during pregnancy or delivery. The baby is up to date with their vaccinations.

What is the most likely radiological finding?

Hypertrophic sphincter on ultrasound

Echogenic fibrosis of biliary tree

Bird’s beak appearance on barium swallow

Target sign on the ultrasound

Double-bubble sign on abdominal X-ray

Answer 18

Target sign on the ultrasound
This child has intussusception. They have typical features, including colicky abdomen pain, discomfort after eating and the unique redcurrant jelly stool. The first-line investigation is ultrasound; characteristic findings include a target sign. The target sign shows the telescoped part of the bowel within the normal bowel.

Question 19

A 12-month old child with severe intermittent abdominal pain in the right iliac fossa is seen in the Paediatric Assessment Unit with bilious vomiting, abdominal distension and passage of stool with blood-stained mucus. An ultrasound scan shows concentric echogenic and hypoechogenic bands.

Given the information provided, which of the following is the most likely diagnosis?

Complete small-bowel obstruction

Malrotation

Intussusception

Acute appendicitis

Acute pancreatitis

Answer 19

Intussusception
Intussusception typically presents with reduced feeding, bile-stained vomiting, abdominal distension, and passage of ‘redcurrant jelly’ stool (with blood-stained mucus). The pain is often intermittent and is severe during attacks. A classic ‘target’ sign on abdominal ultrasound is seen as concentric echogenic and hypogenic bands, demonstrating the invagination of a bowel segment into an adjacent one.

Complete small-bowel obstruction
This patient is unlikely to have complete small-bowel obstruction as they are able to pass stool and their pain is intermittent. This patient is more likely to have intussusception, due to the intermittent pain, passage of ‘redcurrant jelly’ stool and ‘target’ sign on ultrasound scan.
4% of users selected this answer.

Malrotation
Malrotation would present with complete bowel obstruction and dark green bilious vomiting and is diagnosed by contrast study, which may show a corkscrew-shaped proximal bowel. This patient is more likely to have intussusception, due to the intermittent pain, passage of ‘redcurrant jelly’ stool and ‘target’ sign on ultrasound scan.
17% of users selected this answer.

Intussusception
Intussusception typically presents with reduced feeding, bile-stained vomiting, abdominal distension, and passage of ‘redcurrant jelly’ stool (with blood-stained mucus). The pain is often intermittent and is severe during attacks. A classic ‘target’ sign on abdominal ultrasound is seen as concentric echogenic and hypogenic bands, demonstrating the invagination of a bowel segment into an adjacent one.
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Acute appendicitis
Pain with appendicitis is usually constant, rather than intermittent. The other signs, such as passage of ‘redcurrant jelly’ stool and ‘target’ sign on ultrasound scan, are more indicative of intussusception.
2% of users selected this answer.

Acute pancreatitis
This patient is unlikely to have pancreatitis, as their pain is intermittent and more in the lower iliac fossa than the epigastric region. This patient is more likely to have intussusception, due to the intermittent pain, passage of ‘redcurrant jelly’ stool and ‘target’ sign on ultrasound scan.

Question 20

A 3 month old baby boy is brought to A&E because today he has been crying inconsolably and he had had strange poos. The stool is red and goopy. He has also vomited milky fluid twice today. He has not had a fever.

On inspection, the child appears unwell and is screaming. It is difficult to properly examine the chest or abdomen because he is inconsolable. An abdominal ultrasound shows concentric rings of hyper- and hypo-echogenicity.

What is the best option to manage this child’s condition?

Anterior resection

Appendicectomy

Movicol disimpaction regimen

Ciprofloxacin

Rectal air insufflation

Answer 20

Rectal air insufflation
This boy with inconsolable crying and currant-jelly stool most likely has intussusception. Intussusception is a condition where one part of bowel telescopes into an adjacent segment. It is managed with rectal air insufflation in theatre

Anterior resection
Anterior resection is an operation performed to remove high rectal tumors
9% of users selected this answer.

Appendicectomy
Surgical removal of the appendix may be decided in a child with a high risk of appendicitis, which is diagnosed through a combination of history, examination, bloods (raised inflammatory markers) and abdominal ultrasound
0% of users selected this answer.

Movicol disimpaction regimen
Movicol disimpaction regimens are used to treat children with faecal impaction in chronic constipation
11% of users selected this answer.

Ciprofloxacin
Ciprofloxacin is used to treat salmonella infection, which can cause blood in the stool. However, the history (particularly mucous-heavy ‘currant jelly stool’ rather than just bloody diarrhoea) and specific ultrasound findings, along with the lack of fever, point to intussusception rather than an infectious cause
4% of users selected this answer.

Question 21

A 6-month-old boy is brought to the paediatric emergency department as his mother is worried about him. He has been crying intermittently for the last 12 hours, appearing to be in pain and drawing his legs up when crying. He has also been refusing feeds for the last 12 hours.

On examination, there is a sausage-shaped mass palpable in the upper right quadrant of the abdomen.

Which of the following is the most likely sign to be seen on abdominal ultrasound in this case?

Double bubble sign

Embryo sign

Coffee bean sign

Target sign

Bird’s beak sign

Answer 21

The target sign, also known as the doughnut sign or bull’s eye sign, is the appearance of alternating echogenic and hypoechoic bands caused by the telescoping of the bowel. This is classically seen in intussusception.

Double bubble sign
Double bubble sign refers to the appearance of 2 gas-filled structures in the abdomen of infants on abdominal x-rays, indicating a distended stomach and duodenum. This is usually caused by duodenal obstruction, which has many aetiologies, the most common being duodenal atresia.
14% of users selected this answer.

Embryo sign
The embryo sign is classically seen on abdominal x-rays in caecal volvulus rather than in intussusception.
1% of users selected this answer.

Coffee bean sign
The coffee bean sign is classically seen on abdominal x-rays in sigmoid volvulus rather than in intussusception.
9% of users selected this answer.

Target sign
This is a classic case of intussusception, where the proximal bowel ‘telescopes’ into a distal segment, causing the baby to experience severe, colicky pain. Other features include abdominal distension, bile-stained vomiting depending on the site of intussusception and passage of ‘redcurrant jelly’ stool (although this is a very late sign).

Bird’s beak sign
Bird’s beak sign is classically seen on a barium swallow where the proximal oesophagus is dilated and then smoothly tapers off in the distal oesophagus in achalasia.

Question 22

A 9-month-old boy is brought to the emergency department by his parents, after vomiting and passing blood in his stool. It is described as bright and quite sticky but they have not brought it in. Over the past 2 days, he has had several episodes of suddenly crying inconsolably, where the episodes have each spontaneously resolved. He has no past medical history.

On examination, he has normal physical observations, appears to be in discomfort, which is exacerbated by the palpation of his soft, non-distended abdomen. His chest examination is normal.

Plain-film x-ray radiograph of the abdomen is normal, and chest radiograph does not demonstrate any free air under the diaphragm.

What is the most appropriate management of this patient’s most likely underlying condition?

Air enema reduction

Observation

IV antibiotics

Endoscopy and local treatment

Urgent laparotomy

Answer 22

Air enema reduction
The 1st line treatment for stable patients with intussusception is radiological reduction using a contrast enema. Most commonly, air enema is used. Alternatively, contrast liquid can be used, such as barium, water-soluble and recently saline. There should be adequate monitoring in place before and during the procedure, with access to resuscitation equipment and expert help should it be required. This would be contraindicated in patients in shock, or who have peritonitis or perforation, for whom surgical reduction is the 1st line treatment.
You and 67% of users selected this answer.

Observation
This would not be appropriate. Fluid resuscitation alone would only deal with hypovolaemia potentially resulting from the condition, but would not address the pathology in intussusception, which requires active reduction (radiological or surgical).
11% of users selected this answer.

IV antibiotics
Although some patients with intussusception are offered antibiotics, this has to be alongside definitive treatment and alone would not deal with the underlying condition.
3% of users selected this answer.

Endoscopy and local treatment
This is the treatment for a patient with an upper GI bleed. The blood in the stool in this case is due to intussusception, not an upper GI bleed. Successful reduction should resolve the passage of blood.
7% of users selected this answer.

Urgent laparotomy
Surgical reduction in intussusception is the first line treatment for an unstable patient (shock, perforation, peritonitis) or where there is a contraindication to enema reduction. It is second line in stable patients, if radiological reduction is not successful. This patient should therefore have radiological reduction first, as the patient is stable, it is a less invasive procedure, and carries a high success rate. Surgery is usually carried out through a right lower quadrant open incision.

Question 23

A 6-month-old male infant presents to the GP with difficulty after feeding. His parents report that following feeding, he pulls his legs up and cries inconsolably. He sometimes refuses feed. They also report that there has been some unusual looking stool. He has not had a fever. An abdominal examination reveals a distended, tender abdomen with a palpable right sided-abdominal mass. The nappy has evidence of redcurrant jelly stools. There have been no concerns since birth and he is up to date with his immunisations.

What is the most appropriate initial investigation?

Laparotomy

Ultrasound

MRI abdomen

CT abdomen

Abdominal X-ray

Answer 23

Ultrasound
This child has intussusception, commonly characterised by colicky abdominal pain, flexing of the legs following feeding, fever, vomiting and blood in the stool. Intussusception most commonly occurs in infants aged between 3 and 12 months. Ultrasound is the most appropriate first line investigation. Treatment involves reduction by contrast enema.

Laparotomy
This is not an appropriate first line investigation as non-invasive methods have not been trialled
8% of users selected this answer.

answer.

MRI abdomen
Although this would likely reveal the diagnosis it is time and resource intensive and so not an appropriate first line investigation
6% of users selected this answer.

CT abdomen
A CT scan would be highly inappropriate in this age group due to exposing the child to ionising radiation
8% of users selected this answer.

Abdominal X-ray
This may be used in conjunction with air enema as a treatment option, however the best initial investigation is with ultrasound as x-ray alone is not the most sensitive
8

Question 24

An 11 month old boy is brought in by his mother. He has been increasingly lethargic over the past 3 days. Over the last day, he has been recurrently kicking his legs in the air. He vomited 3 times yesterday. His mother noticed blood in his nappy this morning which she reports looking like ‘jelly.’ There is no evidence of peritonitis.

He has a heart rate of 100 and blood pressure of 100/60. He is afebrile. US abdomen reveals concentric echogenic and hypoechogenic bands.

What is the best intervention?

IV antibiotics with urgent IV fluids

Technetium scan

Contrast or air enema

Pyloromyotomy

Urgent laparotomy

Answer 24

Contrast or air enema
Contrast enema is correct. This case describes intussusception with ‘target sign’ seen on ultrasound abdomen. It can be used as diagnostic test but also can be used as a method for reduction. Air enema is the may be preferred as the method of choice as offers fewer complications than contrast enema

IV antibiotics with urgent IV fluids
The patient is slightly tachycardic, but there are no other identifiers for sepsis, hence antibiotics may not specifically be needed. However, if his clinical situation deteriorates, such as developing fever or worsening hypotension, they may be indicated
8% of users selected this answer.

Technetium scan
A technetium scan is used to identify Meckel’s diverticulum. It usually presents in an older child (around 2 years old), with painless rectal bleeding. Meckel’s diverticulum may be a cause for intussusception, a technetium scan will delay intervention before complications arise
5% of users selected this answer.

answer.

Pyloromyotomy
Pyloromyotomy is the management for pyloric stenosis. We would expect non-bilious vomiting with no evidence of PR bleeding
7% of users selected this answer.

Urgent laparotomy
Urgent laparotomy may be indicated if the patient remains clinically unstable despite resuscitation or there are signs of bowel obstruction with peritonitis (seen in malrotation or volvulus). This patient is relatively stable