The clinical manifestations of intussusception mainly include abdominal pain, vomiting, bloody stools, and an abdominal mass. The abdominal pain is often spasmodic and regular, manifesting as sudden severe colicky pain. The child appears to be crying and restless, with knees drawn up to the abdomen, pale complexion, and the pain lasts for several minutes or longer but lessens after; it recurs every ten to twenty minutes, accompanied by intestinal movements. Vomiting is an early clinical symptom, initially consisting of milk curds or food residue, and later may include bile and fecal-like liquid. Bloody stool is an important symptom, appearing within the first few hours; initially, the stools can be normal, with about 85% of cases excreting jam-like mucoid bloody stools within six to twelve hours of onset. The abdominal mass is often located in the upper right abdomen below the costal margin, where a slight, tender mass can be palpated.