Age-based paediatric acute abdomen — bilious vomit to intussusception

Neonate bilious vomiting: midgut volvulus secondary to malrotation until proven otherwise — NPO, IV fluids, urgent surgical consult; confirm the contrast/theatre pathway against local paediatric-surgery protocol. Held scope: ultrasound performance for malrotation/volvulus varies, with individual sonographic signs assessed in a multi-institutional review.^[4][5]

Infant intermittent colic ± redcurrant jelly: intussusception — IV access, fluids, urgent ultrasound as the modality of choice for diagnosis; nonoperative enema reduction is the treatment of choice without perforation/peritonitis (80 to 90% success).^[1]

Projectile non-bilious vomiting ~2–8 weeks: pyloric stenosis — confirm electrolyte/fluid-correction and ultrasound specifics against local paediatric protocol.^[3] Always examine hernias and genitalia; in adolescents add torsion/ectopic/β-hCG per local ED protocol.