Most kid stomach aches are constipation, gas, a virus, or stress. Serious: pain localizing to the right lower side, steadily worsening pain, pain waking them at night, green or bloody vomiting, blood in stool, a hard swollen belly, or a kid who refuses to move.
The appendix pattern is movement-sensitive: right-lower pain plus fever, vomiting, and a still, guarded child means same-day evaluation. Toddler-specific: episodic screaming with legs pulled to the chest can be intussusception, an emergency, and a tender groin lump can be a hernia. Watch-at-home is reasonable for the diffuse, crampy, no-fever kid who still plays between waves and keeps fluids down; give it a few hours and a toilet sit, because the fix is often a bowel movement. The recurrent-mornings pattern (belly-button pain for weeks, worse on school days) deserves a pediatric appointment about functional pain and constipation, not repeated urgent care. Trust the behavior test: a kid playing between cramps is usually fine; a kid lying very still is not.
What to do
Common questions
Is my childs stomach pain serious?
Most childhood stomach aches are the unglamorous four: constipation (the most common by far), gas, a stomach virus, or stress and anxiety, which genuinely produce belly pain in kids. The location rule from MedlinePlus helps: pain that is vague and around the belly button is usually benign; pain that localizes, especially to the right lower abdomen, is the appendix pattern. The get-seen-today list: pain that is severe or steadily worsening over hours; pain migrating to the right lower side, especially with fever, vomiting, and a kid who goes still and refuses to jump or walk (movement hurts an inflamed appendix); vomiting that is green (bile) or bloody; blood or mucus in the stool; a hard, swollen, tender belly; pain that wakes the child from sleep repeatedly; or pain with a rash, painful urination, or sore throat. Babies and toddlers get their own signals: legs pulled to the chest with episodic screaming can be intussusception (an emergency), and a tender groin lump can be a hernia. The watch-at-home version: a child who plays between cramps, drinks fluids, has no fever, and hurts diffusely can be watched for several hours with fluids and a toilet sit, since half the time the fix is a bowel movement. The pattern that merits a routine appointment rather than the ER: recurrent belly-button-area pain for weeks with normal exam findings, often tied to school mornings or stress, worth a pediatric conversation about functional abdominal pain and constipation rather than repeated urgent visits.