Intussusception

Introduction

Intussusception is a sudden medical condition where part of the intestine “telescopes” into an adjacent segment, leading to blockage and disturbed blood flow. It most often affects infants and toddlers, but can occur at any age adults included, though that’s rarer. Without prompt treatment, it impacts hydration, causes severe pain, and can threaten the life of the affected child (or adult!). In this article we’ll look at the typical symptoms, what causes intussusception, how it’s diagnosed and treated, and what one can expect in the long run. Buckle up—it’s a bit of a wild ride through the gut.

Definition and Classification

Medically, intussusception refers to the invagination (or “telescoping”) of a proximal bowel segment into the lumen of a distal segment. This leads to obstruction and compromised circulation of the involved intestinal wall. Physicians classify intussusception by several criteria:

• Location: Ileocolic (most common in kids), ileoileal, colocolic.
• Duration: Acute (symptoms under 48 hours) vs. chronic (weeks of intermittent pain).
• Etiology: Idiopathic (no clear lead point, typical in children) vs. secondary (pathological lead point like polyp, Meckel’s diverticulum, or tumor).
• Reducibility: Reducible (responds to non-surgical enema) vs. non-reducible (requires surgery).

It primarily affects the small intestine and the colon, with the terminal ileum sliding into the cecum in many pediatric cases (that ileocolic subgroup). Subtypes like jejunojejunal intussusception exist but are much less common.

Causes and Risk Factors

Intussusception arises when an initial lead point or dysmotility triggers part of the bowel to fold into itself. In young kids, about 90% of cases are idiopathic—no specific lesion is found. Yet, some contributing factors are known:

• Infectious triggers: Adenovirus, rotavirus, or other gut infections can inflame Peyer’s patches (lymphoid tissue), creating a bulge that starts the telescoping.
• Pathological lead points: In older kids and adults, structural abnormalities like Meckel’s diverticulum, polyps, lipomas, or benign/malignant tumors can serve as anchors.
• Genetic predispositions: Certain syndromes (Peutz-Jeghers, cystic fibrosis) increase the odds of small-bowel intussusception.
• Postoperative adhesions or anastomosis sites: Scar tissue after abdominal surgery sometimes act as lead points.
• Age and sex: Peak incidence 6–36 months, slight male predominance (1.5:1).
• Seasonality: Some studies note a spike in late winter or spring when viral gastroenteritis rates climb.

Modifiable risks are few vaccination against rotavirus may reduce some cases, though vaccination itself rarely triggers intussusception (a tiny heightened risk in older formulations). Non-modifiable risks include congenital anomalies, family history, or having endured a bout of abdominal surgery. Importantly, many cases still develop without any clear risk factor, so the cause remains unknown in a significant share of patients.

Pathophysiology (Mechanisms of Disease)

Under normal circumstances, the intestines propel contents smoothly via coordinated peristalsis (wave-like muscle contractions). In intussusception, a lead point (like inflamed lymphoid tissue) catches the bowel wall, and peristalsis drags that segment forward into the distal lumen. From there, several harmful processes unfold:

• Obstruction: The invaginated segment blocks passage of gas and stool, leading to sudden crampy pain and distension.
• Venous congestion: The mesentery supplying the telescoped bowel gets pinched, impairing venous outflow and causing edema—further worsening the blockade.
• Arterial compromise: If left unchecked, arterial inflow also becomes restricted; the bowel wall can become ischemic, progressing to necrosis and perforation.
• Inflammatory cascade: Ischemic tissue triggers local inflammatory mediators, which worsen edema and may create perforations, leading to peritonitis.

Essentially, a vicious cycle of entrapment, obstruction, and impaired blood flow sets in quickly. That’s why intussusception is considered an abdominal emergency requiring prompt recognition and management.

Symptoms and Clinical Presentation

Intussusception typically presents with a tetrad of clinical features, though not every child shows all symptoms at once:

• Colicky abdominal pain: Sudden onset of intense, intermittent pain. Kids may draw up knees, cry inconsolably, then have pain-free intervals. Parents often note episodes every 15–20 minutes.
• Vomiting: Starts non-bilious, can become bilious if the obstruction is high.
• “Red currant jelly” stool: A mix of blood and mucus from mucosal sloughing—seen in fewer than half of patients but considered a classic sign.
• Palpable mass: A sausage-shaped, tender mass in the right upper quadrant or mid-abdomen. Not always found, esp. in very cranky or small infants.

In very early disease, you might only see periods of fussiness and reduced appetite easy to dismiss as a tummy bug. As intussusception progresses, dehydration, lethargy, and signs of peritonitis (fever, guarding, rebound tenderness) can develop. Atypical presentations are common in adults: they may have chronic, intermittent pain mimicking IBS or Crohn’s disease. Always consider intussusception in any patient with unexplained cyclical abdominal pain.

Urgent warning signs: persistent bilious vomiting, distended/tender abdomen, signs of shock (pallor, tachycardia, hypotension), or peritoneal signs demand immediate ER evaluation.

Diagnosis and Medical Evaluation

Because intussusception can masquerade as viral gastroenteritis, high suspicion is key. The diagnostic pathway often includes:

• Clinical exam: History of intermittent pain, vomiting, and possible red-tinged stools + palpation for a “sausage” mass.
• Ultrasound: The first-line imaging. A characteristic “target” or “doughnut” sign on transverse view, or “pseudo-kidney” sign in longitudinal view, confirms telescoping bowel loops. It’s non-invasive and fast—though less sensitive in obese patients.
• Air-contrast or hydrostatic enema: Diagnostic and therapeutic. Under fluoroscopy or ultrasound guidance, air (or saline) is introduced through the anus to unfold the intussuscepted bowel. Success rates exceed 80% in uncomplicated pediatric cases.
• CT scan: More common in adults or when ultrasound is inconclusive. CT shows the classic “target” lesion and can help identify a lead point like a tumor.
• Lab tests: Not diagnostic but assess hydration (electrolytes), infection markers (CBC), and coagulation status before reduction attempts.

Differential diagnoses include gastroenteritis, volvulus, appendicitis, mesenteric adenitis, or constipation. A wrong guess can delay treatment, so imaging is crucial when intussusception is on the table.

Which Doctor Should You See for Intussusception?

Wondering which doctor to see for abdominal pain that might be intussusception? In an emergency, head to the nearest ER or call emergency services—don’t wait for an appointment. On arrival, an ER physician or pediatric emergency specialist typically leads initial evaluation. If imaging confirms intussusception, a radiologist often performs the enema reduction under fluoroscopy or ultrasound guidance.

For surgical cases (failed reduction or suspicion of perforation), a pediatric or general surgeon steps in. Adults may be managed by a general surgeon or a gastroenterologist, depending on the local setup. Post-reduction or post-op follow-up can involve a pediatrician or a primary care physician.

Telemedicine can be helpful for:

• Discussing initial symptoms and whether urgent evaluation is needed
• Getting a second opinion on imaging—many radiologists offer remote reads
• Clarifying instructions after discharge, e.g. how to watch for recurrence

But remember: online care complements in-person exams—it doesn’t replace the need for a hands-on physical exam or emergency interventions if the child is acutely ill.

Treatment Options and Management

Evidence-based management of intussusception comprises:

• Non-surgical reduction: Air-contrast or hydrostatic (saline) enema under imaging guidance is the first-line in stable pediatric patients without peritonitis. It usually works on the first or second attempt. Risks include bowel perforation (rare, ~1–3%).
• Surgical intervention: Indicated if non-surgical reduction fails, if there's evidence of perforation, peritonitis, or a pathological lead point. The surgeon manually reduces the intussusception or resects necrotic bowel segments. Post-op ileus and wound infection are potential complications.
• Supportive care: IV fluids to correct dehydration, analgesia (often acetaminophen or judicious morphine), correction of electrolytes, and NPO (nothing by mouth) status until reduction is achieved.
• Recurrent cases: Sometimes repeat enemas suffice; if recurrent, surgery may include fixation procedures (e.g. enteroplication), though these are uncommon.

Longer-term, children recover rapidly usually back to normal diet within 24 hours if enema succeeds. Adults may need more extensive surgery and monitoring for complications.

Prognosis and Possible Complications

When diagnosed and treated quickly, intussusception has an excellent prognosis over 95% of pediatric cases resolve without long-term issues. Recurrence occurs in about 5–10% of children, typically within 24–48 hours, so observation for a while in the hospital is standard. Prognosis worsens if:

• Treatment is delayed >48 hours (risk of necrosis and perforation rises).
• There’s a pathological lead point requiring bowel resection.
• The patient has comorbid issues (immunodeficiency, congenital heart disease, etc.)

Possible complications include perforation during reduction (<3%), peritonitis, sepsis, and long-term adhesions leading to small-bowel obstruction. Adult cases have a slightly higher risk of complications due to underlying pathologies and more invasive surgeries.

Prevention and Risk Reduction

Because many pediatric intussusceptions are idiopathic, there's no guaranteed prevention. Yet some strategies may help reduce overall risk:

• Rotavirus vaccination: Widely adopted in many countries, it halves the incidence of rotavirus infection, a known trigger. Be aware that older vaccine formulations briefly increased intussusception risk in the week following the shot, but current vaccines carry a very small net risk.
• Prompt treatment of gut infections: Managing dehydration and preventing severe inflammation can potentially reduce episodes of lymphoid hyperplasia.
• Surveillance in high-risk groups: Children with cystic fibrosis or Peutz-Jeghers syndrome should have regular GI check-ups to detect polyps early.
• Educating caregivers: Teaching parents to recognize cyclical abdominal pain, vomiting, and red-tinged stools can lead to faster ER visits.

Screening for intussusception isn’t practical in healthy kids; focus instead on general gut health, vaccinations, and awareness of symptoms.

Myths and Realities

Intussusception often sparks confusion and even fear in parents—here are some common myths:

• Myth: “Only babies get intussusception.” Reality: While most cases are in infants (peak 6–36 months), older kids and adults can develop it, often due to a pathologic lead point.
• Myth: “A normal ultrasound rules it out.” Reality: Ultrasound is very sensitive but not infallible—re-scanning or alternate imaging (CT) may be needed if suspicion remains high.
• Myth: “If my child has red jelly stool, it’s definitely intussusception.” Reality: That stool is suggestive but appears in fewer than half of cases. Other GI conditions can cause bloody mucus stools.
• Myth: “Intussusception always needs surgery.” Reality: Most pediatric cases reduce non-surgically via air or hydrostatic enema; surgery is reserved for failures or complications.
• Myth: “A bout of intussusception means lifelong gut problems.” Reality: Recurrence is uncommon (<10%), and long-term outcomes are excellent when treated promptly.

Conclusion

Intussusception is a serious but treatable form of bowel obstruction, especially in young children. Prompt recognition through intermittent abdominal pain, vomiting, and imaging allows for non-surgical reduction in most cases, leading to rapid recovery. Complications like bowel necrosis or perforation become more likely if diagnosis or treatment is delayed. For adults, underlying lesions often require surgical removal. Telemedicine can help guide families toward timely in-person care, but hands-on evaluation remains indispensable. If you suspect intussusception be it your toddler cradling their belly in pain or unusual chronic pain in yourself—seek immediate professional attention for the best outcomes.

Frequently Asked Questions (FAQ)

• Q1: What age is most at risk for intussusception?
• A1: Most cases occur in infants 6–36 months old, though it can affect older children and adults.
• Q2: What causes the “telescoping” of intestine?
• A2: A lead point—like inflamed lymph nodes or a polyp—plus normal peristalsis drags the bowel inward.
• Q3: Can intussusception occur after rotavirus vaccine?
• A3: Early vaccine versions had a slight risk; modern vaccines carry minimal increased risk, and overall benefits outweigh it.
• Q4: Is ultrasound enough to diagnose?
• A4: It’s first-line with high sensitivity, but CT or repeat imaging can help if ultrasound is inconclusive.
• Q5: What is a red currant jelly stool?
• A5: It’s stool mixed with blood and mucus, classic but only in about 50% of cases.
• Q6: How is it treated non-surgically?
• A6: A guided air or saline enema under imaging pressure unfolds the bowel in most pediatric patients.
• Q7: When is surgery required?
• A7: Surgery’s needed if enema fails, bowel is perforated, or a suspicious lead point is found.
• Q8: Can intussusception recur?
• A8: Yes, in about 5–10% of children, usually within 48 hours; observation post-reduction helps catch it early.
• Q9: What complications occur if untreated?
• A9: Bowel necrosis, perforation, peritonitis, sepsis, and even death if delayed.
• Q10: Who should I see first?
• A10: In emergencies, visit the ER. Later, a pediatrician or surgeon will guide definitive care.
• Q11: Can adults get intussusception?
• A11: Yes, often due to tumors or polyps serving as pathological lead points.
• Q12: How long is the hospital stay?
• A12: Typically 1–2 days if enema reduction succeeds, longer for surgery or complications.
• Q13: Is telemedicine useful?
• A13: It helps with initial advice, second opinions on scans, and post-discharge follow-up, but not for emergent exams.
• Q14: How can I reduce risk?
• A14: Vaccinate against rotavirus, treat gut infections early, and monitor high-risk groups regularly.
• Q15: Does prior intussusception affect long-term gut health?
• A15: Almost always no—children typically regain normal GI function once treated.