Intussusception: Symptoms, Types, Causes and Treatment

Intussusception is a medical condition where a segment of the intestine "telescopes" into an adjacent part, causing obstruction, compromised blood flow, and potentially serious consequences if not treated promptly. While it is most commonly seen in infants and young children, intussusception can also occur in adults, where it often presents differently and is usually linked to an underlying cause. This article explores the symptoms, types, causes, and treatments of intussusception, synthesizing the latest research to provide a comprehensive understanding for both lay readers and medical professionals.

Symptoms of Intussusception

Intussusception can be a dramatic and frightening condition, presenting with a range of symptoms that often differ between children and adults. Recognizing these symptoms is crucial, as early diagnosis and treatment can significantly improve outcomes. However, the signs can be subtle or atypical, especially in adults, making awareness all the more important.

Symptom	Description	Age Group	Source(s)
Abdominal Pain	Intermittent, severe, colicky	Both	1234571115
Vomiting	Can be bilious or non-bilious	Both	34511
Bloody Stool	"Currant jelly" appearance	Mainly children	34511
Palpable Mass	Sausage-shaped abdominal mass	Mainly children	3411
Lethargy	Listlessness, fatigue	Mainly infants	5
Obstruction	Constipation, distention	Both	1271115
Nausea	Often with vomiting	Both	2511
Rectal Bleeding	Red blood per rectum	Both	11115

Table 1: Key Symptoms

Common Presentations in Children

• Classic Triad: The classic triad of abdominal pain, vomiting, and bloody stools is well recognized but seen in less than one-third of pediatric cases. Many children present with only one or two of these symptoms, making diagnosis challenging. A palpable "sausage-shaped" abdominal mass is found in some, but not all, cases 341011.
• Other Signs: Infants may also exhibit lethargy, irritability, or sudden onset of inconsolable crying. Vomiting may be the first sign, and stools classically appear as "currant jelly" due to the mixture of blood and mucus 345.

Adult Symptomatology

• Non-Specific and Often Intermittent: Adults typically present with more subtle and non-specific symptoms, such as intermittent crampy abdominal pain, nausea, vomiting, and sometimes rectal bleeding. Symptoms may mimic other gastrointestinal conditions, leading to delays in diagnosis 1271115.
• Obstruction: Many adults develop signs of bowel obstruction, including constipation, abdominal distention, and sometimes a palpable mass. Colicky pain that comes and goes is characteristic 127811.
• Chronicity: Unlike children, adults may have a more chronic or intermittent course, with symptoms persisting for weeks or even months before diagnosis 12715.

Differences Between Children and Adults

• Children: More likely to present acutely, often with the classic triad or a sudden onset of symptoms.
• Adults: Tend to have a longer, more insidious course, with non-specific complaints and a high rate of underlying pathology contributing to the intussusception.

When to Seek Medical Attention

• Any child or adult exhibiting severe, persistent abdominal pain, vomiting, blood in the stool, or signs of bowel obstruction should be evaluated promptly for intussusception.

Types of Intussusception

Intussusception is classified based on the location and segments of the gastrointestinal tract involved. Understanding these types helps guide diagnosis and management, as the underlying causes and risks differ between children and adults.

Type	Location Involved	Age Group	Source(s)
Ileocolic	Ileum into colon	Children	341016
Ileoileal	Ileum into ileum	Both	2816
Jejunojejunal	Jejunum into jejunum	Both	28
Colocolic	Colon into colon	Adults	267811
Ileocecal	Terminal ileum into cecum	Both	27816
Enteric	Small intestine segments	Adults	267816
Gastroduodenal	Stomach into duodenum	Rare/Adults	815

Table 2: Types of Intussusception

Pediatric Types

• Ileocolic: The most common type in children, with the terminal ileum telescoping into the colon. This form is usually idiopathic and responds well to non-surgical reduction 341016.
• Other Types: Ileoileal and jejunojejunal types are less frequent and may have different causes, including polyps or Meckel's diverticulum 816.

Adult Types

• More Varied and Often Secondary: Adults experience a wider variety of types. Enteric (small bowel) intussusceptions are most common, but colonic and ileocolic forms are also seen 26781316.
• Colocolic and Ileocecal: These types are more likely to have a malignant cause in adults and often require surgical intervention 26781314.
• Rare Types: Unusual locations like gastroduodenal or jejunogastric intussusception can occur, typically in adults with surgical history or other predisposing factors 815.

Classification in Clinical Practice

• By Location:
  • Enteric: Involving only the small intestine.
  • Ileocolic/Ileocecal: Involving the terminal ileum and colon.
  • Colocolic: Involving only the colon.
• By Cause:
  • Idiopathic: No identifiable lead point, most common in children.
  • Secondary: Due to a lesion or abnormality, most common in adults 2616.

Causes of Intussusception

The causes of intussusception differ significantly between children and adults. In children, the condition is usually idiopathic, while in adults, a structural "lead point" is often identified.

Cause Type	Example(s) / Details	Age Group	Source(s)
Idiopathic	No identifiable lead point	Children	34916
Lymphoid Hyperplasia	Viral infections (adenovirus, rotavirus)	Children	31216
Polyps	Juvenile or inflammatory	Both	916
Meckel's Diverticulum	Congenital pouch in intestine	Both	8916
Tumors (Benign)	Lipoma, adenoma	Both (adults)	26781316
Tumors (Malignant)	Adenocarcinoma, lymphoma, metastasis	Adults	2678131416
Postoperative	Surgical scars, feeding tubes	Adults	91116
Infections	Adenovirus, rotavirus, enterovirus	Children	512
Iatrogenic	Feeding tubes, post-surgical changes	Adults	1116

Table 3: Major Causes of Intussusception

Pediatric Causes

• Idiopathic: Most childhood cases are idiopathic, with no clear lead point. Hyperplasia of lymphoid tissue in the terminal ileum, often following viral infections (such as adenovirus or rotavirus), is a suspected mechanism 3491216.
• Infectious Triggers: Studies have shown an association with non-enteric adenoviruses, enterovirus B, and, to a lesser degree, rotavirus. The first licensed rotavirus vaccine was linked to a small increased risk, but newer vaccines have not shown this association 3512.
• Structural Causes: Polyps, Meckel's diverticulum, and other congenital anomalies are less common but important causes, especially in older children 8916.

Adult Causes

• Lead Point Lesions: In adults, up to 90% of cases have an identifiable cause. Tumors are the most frequent, with a roughly equal split between benign and malignant lesions. Benign causes include lipomas, polyps, and Meckel's diverticulum, while malignant causes include primary adenocarcinoma, lymphoma, and metastatic tumors 2678131416.
• Benign vs. Malignant:
  • Small Bowel: More likely to be benign or metastatic.
  • Colon: More likely to be primary malignant (adenocarcinoma) 67131416.
• Postoperative and Iatrogenic: Bowel manipulation, surgical scars, and feeding tubes can occasionally act as lead points in adults 91116.
• Idiopathic in Adults: Less common than in children, but still possible in up to 10–20% of adult cases 61116.

Emerging and Rare Causes

• COVID-19: There are case reports of infants with intussusception and concurrent SARS-CoV-2 infection, though causality is unproven 5.
• Other Factors: Rarely, foreign bodies or inflammatory bowel disease may act as triggers 811.

Treatment of Intussusception

Timely and appropriate treatment is essential to prevent serious complications from intussusception. The approach depends heavily on the patient's age, the type and location of intussusception, and the presence of underlying causes.

Approach	Main Method(s)	Age Group	Source(s)
Non-surgical	Air/barium/hydrostatic enema	Children	341016
Surgical	Resection, reduction	Both	12671113141516
Observation	Selected asymptomatic adults	Adults	16
Antibiotics	Supportive, pre/post-surgery	Both	3411
Laparoscopy	Minimally invasive surgery	Both	715

Table 4: Treatment Approaches

Pediatric Treatment

• Non-surgical Reduction: The majority of children are treated successfully with non-surgical methods. Air, barium, or hydrostatic (saline) enemas under imaging guidance are highly effective, with success rates exceeding 80–90% for idiopathic ileocolic intussusception 341016.
  • Advantages: Minimally invasive, avoids anesthesia and surgical risks.
  • Indications: Stable children without signs of perforation or peritonitis.
• Surgery: Required for failed non-surgical reduction, evidence of bowel perforation, peritonitis, or when a pathological lead point is suspected.
  • Procedures: Manual reduction of the intussusception, or resection if the bowel is nonviable or a lead point is present 341016.

Adult Treatment

• Surgical Resection: Surgery is the mainstay of treatment in adults, due to the high likelihood of an underlying lesion, especially malignancy 12671113141516.
  • Small Bowel Intussusception: If malignancy is not suspected and the bowel appears viable, reduction followed by limited resection may be considered 267131416.
  • Colonic Intussusception: Oncologic principles dictate en bloc resection without prior reduction, to minimize tumor spread 613141516.
  • Laparoscopy: Increasingly used for selected cases, with benefits of less pain and quicker recovery 715.
• Non-Surgical Management: Rarely, transient, short-segment, asymptomatic intussusceptions seen on imaging may be observed, especially if no lead point is identified 16.
• Supportive Care: Fluid resuscitation, antibiotics, and stabilization are essential pre- and post-operatively in both children and adults 3411.

Special Considerations

• Recurrence: About 10% of pediatric cases may recur, sometimes requiring repeat reduction or surgery 3.
• Complications: Delays in treatment can lead to bowel necrosis, perforation, sepsis, or even death, especially in infants and the elderly 35611.

Conclusion

Intussusception is a serious medical condition requiring prompt recognition and management. While most common in children, it also affects adults, where it is often secondary to a pathological lesion.

Key points:

• Symptoms: Abdominal pain, vomiting, bloody stools, and signs of bowel obstruction are hallmark symptoms, but presentation varies by age.
• Types: Classified by anatomical location—ileocolic is most common in children, while adults show more variety.
• Causes: Usually idiopathic in children; in adults, a lead point (often a tumor) is usually found.
• Treatment: Non-surgical reduction is preferred in children. Surgery is almost always required in adults, especially when malignancy is suspected.

Early diagnosis and tailored management are critical for optimal outcomes in both pediatric and adult patients with intussusception.