A tummy ache that won't settle

Start with the boring answer, because it is usually right

Constipation is the most commonly missed cause, and the AAP puts it plainly: while it is rarely a problem in younger infants, constipation is a common cause of pain in older children, especially in the lower part of the abdomen.

The reason it gets missed is that parents rule it out too fast. A child who is passing something every day can still be constipated — what matters is whether they are emptying, and a firm mass can sit there while softer stool moves around it. Ask about hard, painful or pebble-like stools over the past week, not just today.

Viruses are the other everyday explanation, and they often announce themselves within a few hours with vomiting or diarrhea. Hunger, trapped wind and a big meal account for a lot of the rest.

The pattern tells you more than the pain

There are broadly three shapes, and sorting which one you are looking at is most of the work.

Pain that comes and goes while the child carries on playing between times is the most reassuring. Pain that is constant and slowly getting worse over hours is the one that needs watching closely. Pain that arrives in severe waves with the child completely well in between is a specific and urgent pattern of its own — see below.

The AAP gives a usable clock for the middle case: if the complaints continue or worsen over a period of three to five hours, or there is fever, a severe sore throat, or an extreme and lasting change in appetite or energy, notify your pediatrician immediately.

The one that comes in waves

This is the pattern most worth being able to recognize, because it is easy to misread as a passing gripe and it is a genuine emergency.

In intussusception, one part of the bowel slides into the next, KidsHealth's description being much like the pieces of a telescope. The pain begins suddenly and comes and goes — and between the episodes the child may stop crying for a while and seem to feel better. That gap is what fools people. The child looks fine, so the visit gets postponed, and then the next wave arrives.

During an episode they typically draw their knees up toward the chest and cry very loudly. Other signs are a swollen belly, vomiting, weakness, fever and drowsiness, and — later — stools mixed with blood and mucus, which is described as currant jelly stool. Do not wait for that; it is a late sign.

KidsHealth puts it as most common in babies five to nine months old, though older children can have it too, and the AAP's own symptom guidance gives a peak age of six months to two years. It is a medical emergency that needs care right away, and most children treated within the first twenty-four hours recover completely.

The one that moves

Appendicitis has a signature that is genuinely useful, because it is about travel rather than location.

The NHS describes pain starting in the middle of the abdomen, around the belly button, and then after a few hours moving to the lower right side. It gets worse when you move, cough, or press on the area, and it may feel slightly better with the knees pulled up to the chest.

The AAP's description matches: a constant stomachache in the center of the abdomen, with the pain later moving down and over to the right side. Nausea, vomiting, a mild fever and loss of appetite typically follow the pain rather than leading it — a child who vomits first and develops pain later is more likely to have a bug.

It is genuinely harder to spot in young children, and the NHS notes atypical presentations are more likely in them. It is rare under twelve months and most common in older children, but rare is not never.

The hop test

This is the most useful thing on this page and it takes ten seconds. The AAP's guidance for suspecting appendicitis is: pain low on the right side and walking bent over, with other signs being that the child will not hop and wants to lie still.

So ask them to jump up and down, or to hop on one foot. A child who bounces around the room has told you something meaningful. A child who refuses, or who does it and clearly hurts, has told you something too.

The same logic applies to the car journey — pain that is noticeably worse over speed bumps is the same signal as pain worse on coughing or movement.

This is a discriminator, not a diagnosis. A child who hops happily can still be unwell, and the three-to-five-hour rule above still applies. But it is real information, and it is the sort of thing a doctor will ask you on the phone.

Things that hurt the tummy but are not the tummy

Urinary tract infections are the classic one. The AAP notes they are much more common in one- to five-year-old children, especially girls, than in infants, and in a small child they often show up as abdominal pain and fever with none of the burning or urgency an adult would report. A tummy ache with an unexplained fever and no other symptoms is worth a urine test.

Strep throat can present with stomach pain, sometimes more prominently than the sore throat itself.

In a boy, this one matters and it is time-critical: testicular torsion. The AAP notes the testicular pain may come with abdominal pain and nausea or vomiting, so a boy reporting tummy pain should always be asked directly about his groin and testicles. Their instruction is specific — go straight to a hospital emergency department, because urgent care does not usually have ultrasound available. The testicle cannot be saved if blood flow is cut off for too long.

The recurring ache with nothing else attached

Some children get tummy aches over and over, always without fever, always without vomiting, and often at recognisable times — school mornings, bedtime, before a particular activity.

The AAP names emotional upset as a genuine cause of recurrent abdominal pain with no other obvious cause. It says this rarely occurs before age five, but that it can happen to a younger child under unusual stress.

The important thing is that this pain is real. It is not pretending, and treating it as pretending tends to make it worse. The stomach is a place small children genuinely feel worry, and the sensation is not imagined.

It still deserves a proper look first, because recurrent pain is also how constipation and a few other things present. Once the physical causes have been considered, the useful conversation is about what is happening around the times it appears.

Get them seen now if

Pain comes in severe waves with calm periods in between, especially between six months and two years.

The pain is low on the right side, or they walk bent over, will not hop, or want to lie completely still.

They are under two years old — the AAP lists this on its own as a reason to be seen now.

There is constant pain or crying for more than two hours.

The vomit is green or yellow, or there is blood in the vomit or the stool.

The tummy is swollen, hard, or painful to touch.

A boy has any pain in the testicle or groin alongside it — emergency department, not urgent care.

There has been a recent injury to the stomach, they are too weak to stand, or they simply look or act very sick.