Tummy Ache in Children: Common Causes and Emergency Signs

"My tummy hurts." Few sentences are heard as often from a child, on waking up, before school, after a meal or in the middle of the night. A child's tummy ache is most often harmless and passes by itself. But a few situations, rare ones, call for the emergency department without waiting, and those are the ones you need to be able to recognise.

A small tummy is a poor messenger: a 3-year-old points to their belly button for almost every pain, and a baby points to nothing at all. Here is how to sort out the common causes, spot the warning signs and react to tummy aches that keep coming back.

What are the most common causes of tummy ache?

The vast majority of abdominal pains in children have an ordinary cause.

Constipation is one of the most common in older children, with pain often felt low in the tummy. The American Academy of Pediatrics (AAP) links it to a diet low in fluids, fruit, vegetables and fibre. A little one who holds on because it hurt once quickly enters a vicious circle. A potty of the right size, where they feel stable, helps them take their time. Our article on constipation in children gives gentle solutions.

Stomach bugs (gastroenteritis) and winter viruses cause cramps, often with diarrhoea and vomiting. The danger in young children is mainly dehydration: see our guide to stomach bugs and dehydration.

Other infections hide behind a tummy ache:

• a sore throat (strep throat), especially after age 2, which combines sore throat, fever and abdominal pain (see sore throat in children);
• a urinary tract infection, common between ages 1 and 5, especially in girls, with burning, frequent urges or leaks, sometimes without fever (see urinary tract infection in children).

More rarely, a cow's milk protein allergy or lactose intolerance, intestinal worms or an overly big festive meal can also be the cause.

When should a tummy ache be a worry?

When it changes character: stronger, longer, more localised, or accompanied by signs that have nothing to do with simple indigestion. The AAP advises contacting the paediatrician without delay if the pain persists or gets worse over three to five hours, if there is fever, a severe sore throat, or a clear change in your child's appetite or energy.

The signs that call for the emergency department, according to the British NHS:

• sudden or very intense pain;
• a tummy that is painful to the touch, that your child protects with a hand, or that is hard;
• green or yellow-green vomit, or vomiting blood;
• blood in the stool, or black stools;
• a child who can no longer pee, poo or pass wind;
• pale, grey or mottled skin, bluish lips;
• a child who is confused, drowsy or not reacting as usual.

Appendicitis: what signs in a child?

Appendicitis usually starts with pain around the belly button, which moves within a few hours to the lower right side of the tummy and gets worse. It increases when the child walks, coughs or when you press on it, and eases a little when they curl their knees up to their tummy. It is often accompanied by nausea, vomiting, loss of appetite and a little fever.

It mostly affects children from 10 and young adults. The AAP calls it very rare before age 3 and uncommon before 5, and in young children the signs are often less typical. Treatment is most often an operation to remove the appendix, done quickly. The NHS warns that pain that suddenly eases and then becomes diffuse and intense may signal an appendix that has burst.

If pain settles low on the right, do not give a painkiller to "see what happens"; see a doctor the same day.

Intussusception, the emergency of the very young

This is the emergency to know between 6 months and 3 years: according to the MSD Manual, 70% of cases occur before age 2. A piece of intestine slides into the next segment, like the tubes of a telescope, and blocks the passage.

The typical picture: sudden bouts of pain that come back every 15 to 20 minutes, often with vomiting. During a bout, the pain is violent and the baby is inconsolable; between bouts, he looks almost normal, which often fools parents. Then he becomes floppy, pale, drowsy. In some toddlers, this unusual listlessness is even the only sign. Later, the stools may contain blood or red mucus "like redcurrant jelly", but this is a late sign: do not wait for it before seeking care.

The good news is that an intussusception caught in time is most often treated without surgery, by an air enema given at the hospital, which succeeds in more than 8 cases out of 10. It can come back, sometimes within the following days: the team will tell you which signs to watch for at home.

Your baby has a tummy ache: how can you tell?

Before they talk, pain shows in behaviour: inconsolable crying, legs drawn up, a tight tummy, refusing to feed, restless sleep. In a young infant, evening crying without other signs is often due to harmless infant colic. What should alert you is the combination with fever, repeated or green vomiting, blood in the stool, refusing to drink or an unusually floppy baby.

Repeated tummy aches: could it be stress?

In school-age children, pains that keep coming back, without fever, vomiting or weight loss, are often functional: the pain is real, but no organ is diseased. The AAP states that they rarely start before age 5, last more than a week and often coincide with a tense period: the start of the school year, a falling-out with a friend, the arrival of a baby, a move, a bereavement or parents separating.

Have your child examined once to rule out another cause. After that, the most useful thing is to listen without dramatising or brushing off the complaint, to keep the school routine, and to check that they drink enough and go to the toilet regularly. On the first day of school or before a test, a breakfast eaten without rushing and a few minutes of cuddles sometimes do more than a syrup.

Pain that wakes your child at night, weight loss, slowed growth, blood in the stool or repeated vomiting are not consistent with simple stress: they call for a check-up.