What It Is
Intussusception is a segment of intestine invaginating (telescoping) into the adjoining lumen, causing obstruction. It happens most often at the ileocolic junction but can occur anywhere in the tract. The invagination runs from above downward, the upper portion slipping over the lower and dragging the mesentery with it.
Pathophysiology
The mechanism is not well established, but it is thought to follow an imbalance in the longitudinal forces along the intestinal wall. A segment (the intussusceptum) telescopes into the receiving bowel (the intussuscipiens), and as more proximal bowel follows it advances along the lumen. If the mesentery is lax and progression is rapid, the intussusceptum can reach the distal colon or sigmoid and even prolapse out the anus. The mesentery is dragged in with it, producing the classic process of any bowel obstruction.
Statistics and Incidences
Incidence varies widely by geography, so true prevalence is hard to pin down. Estimated incidence is about 1 case per 2000 live births; in Great Britain it ranges from 1.6 to 4 cases per 1000 live births. The male-to-female ratio is about 3:1 overall and becomes more marked with age, reaching 8:1 in patients older than 4 years. Two-thirds of affected children are younger than 1 year, most commonly infants aged 5 to 10 months, and it is the most common cause of intestinal obstruction in patients aged 5 months to 3 years. It accounts for as many as 25% of abdominal surgical emergencies in children younger than 5 years, exceeding appendicitis.
Causes
Usually no cause is found. Hyperperistalsis can grab a lead point and pull it and the intestinal lining into the bowel ahead of it. The unusual mobility of the cecum and ileum normal in early life may also contribute.
Clinical Manifestations
The classic triad of vomiting, abdominal pain, and passage of blood per rectum occurs in only one-third of patients. Pain is colicky, severe, and intermittent; rarely parents report one or more prior attacks within 10 days to 6 months before the current episode. Vomiting is initially nonbilious and reflexive, then becomes bilious once obstruction sets in. Currant jelly stool, a mix of mucus, sloughed mucosa, and blood, is a hallmark. Lethargy is a common presenting symptom and, oddly, is not described with other forms of intestinal obstruction.
Assessment and Diagnostic Findings
A rectal exam during a calm interval and palpation (often needing sedation, since the baby resists) may reveal a sausage-shaped mass through the abdominal wall. Plain abdominal radiography suggests intussusception in only 60% of cases; early signs include absent air in the right lower and upper quadrants and a right upper quadrant soft tissue density, present in 25 to 60% of patients. Ultrasonography had reported sensitivity and specificity of 97.9% and 97.8% for ileocolic intussusception and should be the first-line study. CT has been proposed but its findings are unreliable and it adds contrast, radiation, and sedation risk. The traditional, most reliable diagnostic is a contrast enema (barium or air), which is quick, reliable, and potentially therapeutic.
Medical Management
Unlike pyloric stenosis, this is a true emergency where delay is dangerous. Start IV fluid resuscitation and nasogastric decompression as soon as possible. Therapeutic enemas can be hydrostatic (barium or water-soluble contrast) or pneumatic (air insufflation) under fluoroscopic or ultrasonographic guidance; the method matters less than the radiologist's comfort with it. If nonoperative reduction fails or perforation is present, refer promptly for surgery; recurrence after operative reduction is less than 5%. Laparoscopy can be used in all cases for reduction, confirmation of radiologic reduction, and detection of lead points.
Pharmacologic Management
Drug therapy is not part of standard care beyond postoperative pain control. In the immediate postoperative period, weight-adjusted IV morphine is usually given.
Nursing Management
Nursing Assessment
The hallmark findings are a right hypochondrium sausage-shaped mass with emptiness in the right lower quadrant (Dance sign). The typical patient is an infant, often after an upper respiratory infection, presenting with vomiting, abdominal pain, passage of blood and mucus, lethargy, and a palpable mass.
Nursing Diagnoses
- Acute pain related to bowel invagination.
- Deficient fluid volume related to vomiting, nausea, fever, and diaphoresis.
- Ineffective breathing pattern related to abdominal distention and rigidity.
- Anxiety related to change in health status.
Nursing Care Planning and Goals
- Patient has stable vital signs.
- Patient shows balanced intake and output.
- Patient's pain decreases and they are comfortable.
- Patient's breathing pattern becomes effective.
- Caregiver's anxiety resolves.
Nursing Interventions
Give IV fluids as ordered, and blood or plasma if the patient is in shock. Insert a nasogastric tube to decompress the bowel. Replace lost volume as ordered and monitor intake and output. Teach the family what happens in intussusception and during surgery, and answer questions to reduce anxiety.
Evaluation
Goals are met when the patient has stable vital signs, balanced intake and output, decreased pain and comfort, an effective breathing pattern, and the caregiver's anxiety is resolved.
Documentation Guidelines
Document individual findings and behavior, intake and output, characteristics of vomitus, cultural and religious beliefs and expectations, plan of care, teaching plan, responses to interventions and teaching, and progress toward outcomes.
Frequently Asked Questions
What age group does intussusception most often affect? It is most common in infants, with about two-thirds of cases occurring before age 1 and a peak around 5 to 10 months. It is the most common cause of intestinal obstruction in children aged about 5 months to 3 years (StatPearls, Child Intussusception).
What is the classic symptom triad? Colicky abdominal pain, a sausage-shaped palpable abdominal mass, and "currant jelly" stool. The bloody, mucus-streaked stool reflects sloughing of ischemic bowel mucosa, so it is a later sign and not required to act.
Why is intussusception a surgical emergency? The telescoped segment drags its mesentery with it, cutting off blood supply. Untreated, this leads to bowel ischemia, perforation, and necrosis, so rapid recognition and resuscitation matter.
How is it usually diagnosed and treated first? Ultrasound is the first-line imaging study, classically showing a "target" or "doughnut" sign. In a stable child without perforation or peritonitis, an air or contrast enema is both diagnostic and therapeutic and reduces most cases without surgery (Merck Manual Professional).
When is surgery needed? Surgery is indicated when enema reduction fails, when there are signs of perforation, peritonitis, or shock, or when a pathologic lead point is suspected. Necrotic bowel is resected.
What does the nurse watch for after reduction? Recurrence, which can happen within the first 24 to 72 hours, along with the return of normal stool, stable vital signs, and adequate intake and output. Report any return of colicky pain, vomiting, or bloody stool right away.