Stomach and Digestive Problems in Children: What’s Normal and What Isn’t

“My tummy hurts” is one of the most common things a child says and one of the least specific. Almost always it is nothing much. Occasionally it is something that needs attention in the next few hours rather than the next few days, and the only useful thing a page like this can do is help you tell the difference.

So the serious patterns come first.

Go to an emergency room now if

• Severe pain that stays in one place, particularly the lower right side of the abdomen
• Green or bright yellow vomit, or vomit with blood, or anything that looks like coffee grounds
• Blood in the stool, black tarry stool, or — in a toddler — stool that looks like redcurrant jelly
• A hard, swollen, rigid abdomen, or a child who will not let you touch it
• Pain that suddenly eased and then came back worse, with a rigid belly
• Episodes of severe pain every 15–20 minutes in an infant or toddler who goes pale, draws up their legs, and then seems briefly fine
• Signs of dehydration (below) in a child who cannot keep fluids down
• Abdominal or groin pain in a boy with a swollen or tender testicle — testicular torsion presents as belly pain and is time-critical
• Forceful, projectile vomiting after every feed in a baby under three months, especially with weight loss

If you are reading that list because one of them is happening, stop reading and go.

Appendicitis, because the pattern is recognisable

Appendicitis is the surgical emergency most likely to walk into a pediatric practice, and it has a sequence that is worth knowing because the sequence is the diagnosis.

Typically it goes: vague pain around the navel first → loss of appetite, which in children is one of the most telling signs → pain migrating to the lower right side over several hours → nausea and vomiting after the pain began → a low fever. The pain is worse with movement, so a child who does not want to walk, or who flinches going over a speed bump, is giving you real information.

The distinction that matters is the order. In gastroenteritis, vomiting usually comes first and the pain is crampy and moves around. In appendicitis, the pain comes first and then settles in one place. That is not a rule you should stake a diagnosis on, and you are not expected to — it is a reason to call rather than wait.

Two cautions. In children under about five, appendicitis frequently does not follow the classic pattern, which is why it is diagnosed late in that age group more often; a young child with unexplained abdominal pain and fever deserves a low threshold. And if the pain suddenly disappears and then returns worse with a rigid abdomen, that can mean the appendix has burst. That is an emergency, not a relief.

If you suspect it: do not give food or drink, in case surgery is needed. Call us or go in.

Constipation, which is the most common and the most undertreated

Most childhood abdominal pain that is not an infection is constipation, and it is routinely missed for two reasons.

First, it can look like diarrhoea. When stool backs up, softer stool leaks around it, so a constipated child may be soiling frequently. Treating that as diarrhoea makes it worse.

Second, it is usually behavioural before it is physical. One painful bowel movement teaches a child to hold on; holding on makes the next one harder and more painful; and the cycle reinforces itself. Common trigger points are potty training, starting school, and any situation where a child does not want to use the toilet available to them.

What helps:

• Fluid first, then fibre. In that order, and this matters — added fibre without added fluid makes constipation worse, which is how well-meant interventions backfire.
• Unhurried, regular toilet time, ideally after meals, with feet supported on a stool so they can push properly. Posture does more than people expect.
• No punishment and no pressure, including for soiling. A child holding on is not being difficult.
• Come and see us before it becomes entrenched. A long-standing cycle often needs a proper plan, sometimes including medication, and undertreating it is the usual mistake. We would far rather see this early than after a year of it.

Vomiting and diarrhoea

Almost always a virus, and almost always the treatment is fluid rather than medicine.

How to rehydrate. Small amounts, often — a spoonful or a few sips every few minutes beats a full glass that comes straight back up. For anything more than mild losses, use an oral rehydration solution rather than water alone or a sports drink: sports drinks are too sugary and can worsen diarrhoea, and plain water alone in an infant carries a real risk of dangerously low sodium. If a baby is breastfeeding, keep going, more often and for shorter stretches.

Food. Return to a normal diet as soon as they will eat. The old advice to restrict to bland foods has been dropped; children recover faster eating normally.

Do not give anti-diarrhoeal medicines to a child unless we have told you to.

Signs of dehydration, which is what you are actually watching for: no urine for eight hours or noticeably fewer wet nappies, no tears when crying, a dry mouth, sunken eyes, unusual sleepiness or floppiness, a sunken soft spot on a baby’s head, or skin that stays pinched when you release it. Any of these in a child who cannot keep fluids down means call us or go in.

Reflux in babies

Most spitting up is not a problem. A baby who brings up milk, seems comfortable, and is gaining weight is doing something normal that will pass — the phrase worth remembering is that a happy spitter needs a change of clothes, not a medicine.

What does need looking at: poor weight gain, refusing feeds or arching and crying with them, blood in what comes up, forceful projectile vomiting, or any of this starting after six months rather than settling. Reflux medication is prescribed far more often than the evidence supports in otherwise well babies, so we will usually want to look at feeding, positioning and volume first.

Tummy pain with no disease behind it, which is still real pain

A sizeable number of children have recurrent abdominal pain with nothing structurally wrong. The gut and the nervous system are closely wired, and pain generated that way hurts exactly as much as pain from an infection.

It often has a pattern: weekday mornings, around school, around a change at home, or in a child who is anxious in ways that have not been named yet. It tends not to wake them at night, and it does not come with weight loss, fever, blood, or vomiting — which is what makes it reassuring rather than dismissible.

Two things not to do. Do not tell a child it is nothing, because it is not nothing and they know it. And do not embark on repeated testing, which rarely finds anything and teaches a child that their body is a problem to be investigated. What helps is an examination to rule out the things worth ruling out, an honest explanation of why real pain can happen without damage, a regular routine, and attention to whatever is going on around it.

Before you remove a food, talk to us

Cutting out a food group is the most common self-prescribed remedy for digestive symptoms, and it is the one most likely to make a diagnosis impossible.

Coeliac disease testing requires gluten to be in the diet. If you remove gluten first and the test comes back negative, that negative means nothing, and the only way to get a usable answer is to reintroduce gluten for weeks. Please test before you cut.

The same logic applies more loosely to dairy and to broad elimination diets: symptoms that improve on a restricted diet do not tell you which food was responsible or whether anything was. And a growing child on a restricted diet needs the nutrition side thought about, which is a conversation rather than a website.

Probiotics, prebiotics, and the microbiome

The old version of this blog had four separate posts on this. Here is the honest consolidation.

The gut microbiome is real, it matters, and the research is genuinely interesting. It is also substantially oversold in the products that cite it. The gap between “the microbiome influences health” and “this supplement will improve your child’s health” is where most of the marketing lives.

What the evidence reasonably supports: specific probiotic strains have modest benefit for specific situations — shortening antibiotic-associated diarrhoea, and a small effect on the duration of acute gastroenteritis. “Modest” is the accurate word. What it does not support is a daily supplement for a well child as general maintenance.

Prebiotics are simply the fibre that feeds those bacteria, which means the reliable version is food: a variety of plants, whole grains, beans, and fermented foods like yoghurt if your child will eat them. Variety matters more than quantity, and food is cheaper and better regulated than capsules.

Two real cautions. Probiotic supplements are not regulated as medicines, so strain and dose on the label are not guaranteed. And they should not be given to children who are immunocompromised, have a central line, or are seriously ill without a provider’s involvement — in that group there are documented harms.

If you want to spend money on your child’s gut, spend it on groceries.

Call us if

• Abdominal pain that keeps recurring, wakes them at night, or is always in the same place
• Constipation that is not resolving, or any soiling
• Diarrhoea lasting more than a week, or any diarrhoea with blood or mucus
• Weight loss, or poor weight gain, alongside digestive symptoms
• Vomiting that keeps returning without diarrhoea
• Heartburn or chest pain in an older child or teenager
• A baby with reflux who is not gaining weight, refusing feeds, or distressed with them
• You are thinking about removing a food group — before you do it
• A family history of coeliac disease or inflammatory bowel disease alongside symptoms
• Pain that is stopping your child going to school

One general thing that actually helps

Most of what keeps a digestive system working is unglamorous: enough fluid, a variety of plants, regular meals, movement, sleep, and an unhurried toilet routine. That is the whole list, and it is the same list whether the concern is constipation, recurrent pain, or nothing in particular.

If you have been carrying a question about your child’s stomach for a while, bring it to a visit. Recurring symptoms are much easier to work out when we can look at the pattern rather than the worst day.

Sources

37. Constipation in infants and children — MedlinePlus Medical Encyclopedia, U.S. National Library of Medicine. https://medlineplus.gov/ency/article/003125.htm

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