Intussusception is a common acute abdominal condition in children, where a segment of the intestine and its mesentery invaginate into an adjacent intestinal segment, potentially causing intestinal obstruction, intestinal edema, or strangulation necrosis. It is most frequently seen in infants under 2 years old, with the highest incidence occurring between 4 to 10 months of age. The condition typically involves the proximal intestine telescoping into the distal intestine, though retrograde intussusception is rare. The presentation varies, but the ileocolic type (where the distal ileum invaginates into the colon) is the most common, accounting for about 80% of cases. The exact cause of intussusception remains unclear, with most cases having no identifiable trigger. A small number of cases are secondary to other conditions, such as abdominal Henoch-Schönlein purpura, intestinal tumors, or polyps. In infants, excessive mobility of the ileocecal region due to an elongated mesentery is a key anatomical factor contributing to the condition.

bubble_chart Clinical Manifestations

1. Sudden onset of paroxysmal crying: Since infants cannot verbalize, they exhibit restless crying, flailing limbs, pale complexion, and a pained expression during episodes, making them difficult to soothe. The episodes resolve spontaneously within minutes to half an hour, but repeated attacks exhaust the child, who often falls into a drowsy sleep during intervals.
2. Vomiting and hematochezia: Vomiting may occur early in the disease as a reflex response. In the advanced stage, due to intestinal obstruction, vomiting becomes frequent and may include fecal matter. About one-third to half of the affected children pass bloody stools shortly after onset, often without fecal content, appearing as dark red jelly-like stools, which are actually a mixture of intestinal fluid and exudated blood. In cases of significant bleeding, the stool may resemble bloody water, or only small streaks of blood may be present. Due to vomiting, hematochezia, and intestinal obstruction, severe dehydration, electrolyte imbalances, high fever, and even shock may manifest in the advanced stage.
3. Positive abdominal signs: Upon repeated careful examination, a mass can often be palpated in the abdomen, typically in the right hypochondrium or upper-middle abdomen. The classic presentation is a sausage- or banana-shaped mass, which holds significant diagnostic value. Because the ileocecal region is telescoped upward into the colon, palpation of the right lower abdomen may reveal a sense of emptiness. A digital rectal exam may detect swollen intestines, a cervix-like intussusception, and the aforementioned emptiness in the right lower abdomen. Blood on the examining glove can aid in diagnosis. If peritonitis or intestinal perforation has already occurred, marked muscle rigidity may be present. Abdominal distension, visible peristalsis, and borborygmi (gurgling sounds) may also be observed in cases of intestinal obstruction.

bubble_chart Auxiliary Examination

1. Blood picture: White blood cells may increase, with a higher proportion of neutrophils.
2. Blood chemistry: Acidosis may be present.
3. Stool microscopy: Fresh red blood cells may be observed.
4. X-ray examination: In cases of intestinal obstruction, standing position may reveal gas-filled intestinal loops and fluid levels. Air enema is the primary diagnostic method via X-ray, and barium enema can also be used for diagnosis, with the typical manifestation being a cup-shaped defect in the contrast agent.

bubble_chart Treatment Measures

1. General supportive therapy: Dehydration and acidosis should be corrected first, and shock should be actively managed if present. Shock is mainly caused by hypovolemia, so aggressive replenishment of crystalloid fluids and plasma is crucial.
2. Non-surgical reduction: Currently, pneumatic reduction under fluoroscopy is commonly performed. The main indications are cases within 24–48 hours of onset, without obvious signs of intestinal necrosis or perforation, and where the intussusception head has not prolapsed through the anus. Reduction should be performed under the guidance of an experienced radiologist, with strict control of pressure and insufflation time to prevent intestinal perforation. Most children can be successfully reduced via pneumatic enema.
3. Surgical treatment: Surgery should be considered in advanced stages where intestinal necrosis, perforation, severe obstruction is suspected, non-surgical reduction fails, or the intussusception is secondary to other intestinal diseases.