Could pain, constipation or illness be behind my child's behaviour?

Your child starts waking at 3am, refuses the car, hits when a coat sleeve goes on or lies on the floor after school. It may resemble an old pattern, but something about it is new: the intensity, timing, setting or speed of change.

The earlier FamilyFX guide on recognising changed behaviour as possible communication explains the first principle. This article takes the next step: organising a physical-health enquiry that a clinician can use.

Define what changed

Begin with the child's own baseline. “More challenging” is broad. Write:

• what the child usually does;
• what is happening now;
• when it began and whether onset was sudden or gradual;
• how often it occurs and how long it lasts;
• settings where it appears or disappears;
• what the child can no longer do;
• new waking, eating, drinking, movement or toilet changes; and
• recent illness, injury, medicine, dental care or routine change.

A child does not have to cry, point to a body part or say “it hurts”. Possible pain may appear as stillness, pacing, aggression, laughter, withdrawal, disturbed sleep, avoiding movement, pressing a body part or losing a skill. None of these proves pain. The change is a reason to look.

NICE says autistic people who develop behaviour that others find difficult should be assessed for possible triggers including physical-health conditions, mental-health problems and environmental factors.¹ These possibilities can coexist.

Make a short body-systems check

This is an observation guide, not a home diagnostic examination.

Mouth, teeth, ears and throat

Notice changes in chewing, drinking, breath, drooling, touching the face, avoiding one side, response to temperature, swallowing, voice, hearing or tolerance of hair and face care. Ask about a dental review for tooth or gum concerns. Ear or throat pain may alter sleep, eating and tolerance of noise or touch.

Breathing and circulation

Look for cough, unusual breathlessness, wheeze, changed colour, reduced activity or difficulty lying down. Breathing difficulty, blue or grey colour, collapse or marked deterioration needs urgent help. Do not attribute rapid breathing during distress to anxiety without considering illness.

Stomach, bowel and urine

Record abdominal pain or guarding, appetite, vomiting, stool frequency and appearance, soiling, withholding, urine frequency, pain on weeing, wetting, unusual thirst and fluid intake.

Constipation can involve hard or infrequent stools, overflow soiling, abdominal pain, poor appetite, withholding and changes in energy or mood.² A child may still pass some stool. Urinary and bowel symptoms can also occur together and require clinical assessment.

Skin and temperature

Check visible skin for rash, swelling, broken areas, eczema, infection, bites or pressure from clothing and equipment. Note a measured temperature where appropriate. A rash that does not fade under pressure in an unwell child requires urgent advice; follow current NHS instructions rather than relying on a photograph.

Movement and injury

Notice limping, avoiding stairs, protecting a limb, changed handwriting or self-care, reluctance to sit, reduced range of movement, weakness or loss of balance. Ask what happened before the change. A child who cannot explain an injury may return to the activity and still be hurt.

Sleep, energy and neurology

Record unusual sleepiness, waking, snoring, breathing pauses, headache, dizziness, staring episodes, seizures, confusion, loss of skill or a changed gait. NICE's autism guidance specifically asks clinicians assessing sleep problems to consider physical discomfort such as reflux, ear or toothache, constipation and eczema, as well as medication and daytime factors.³

Eating, drinking and medication

Note reduced intake, swallowing signs, new restriction, weight change, dehydration signs and the timing of prescribed and non-prescribed medicines. Do not stop a prescribed medicine abruptly unless urgent clinical advice tells you to. Ask the prescriber whether a new symptom or behaviour could be an adverse effect or interaction.

Record what the child does, not what it means

Write “holds right jaw and refuses cold drink” rather than “sensory meltdown”. Write “wakes crying 40 minutes after lying down” rather than “attention seeking”. Include the child's own words, signs or device messages exactly.

A useful one-page record contains:

1. baseline and main change;
2. a dated timeline;
3. observable body signs;
4. eating, drinking, sleep, bowel and urine changes;
5. medicine and recent health events;
6. what school or another carer sees; and
7. what you want assessed.

Record what temporarily helps: changing position, passing stool, eating, pain relief given according to professional directions, warmth, rest or leaving a noisy space. Relief is useful context but does not confirm a diagnosis.

Compare settings carefully

If school sees no problem, ask about function rather than visible distress. Is the child eating, drinking, using the toilet, joining physical activity, concentrating and moving as usual? A child may contain their response, have different demands or deteriorate only after returning home.

If difficulty happens only at school, physical health still remains possible. Noise may worsen a headache, school food may change bowel symptoms, or the child may avoid an inaccessible toilet. Environmental information helps locate the problem; it does not automatically prove a behavioural cause.

Share the minimum health information needed and protect privacy. Ask one named person to note factual changes. Do not ask staff to diagnose pain from behaviour.

Make the appointment answer useful questions

Open with the change and risk, not the neurodevelopmental history:

“For six days, he has woken three times a night, stopped chewing on the left and hits when his jaw is touched. This is new.”

Then ask:

• Which physical causes have been considered?
• Is examination, dental review, testing or another referral needed?
• What can we safely do while waiting?
• When should this be reviewed if it does not settle?
• Which change means earlier or urgent help?

Ask for communication and examination adjustments before the appointment. The child may need extra time, a quieter wait, demonstration before touch, fewer people, familiar support or examination in a different order. An incomplete examination should be recorded honestly rather than presented as a normal finding.

If the clinician finds no immediate cause, that is not proof that the child is well or that the explanation is psychological. It may be reassuring evidence about the things assessed. Agree what happens if symptoms persist, spread or worsen.

Give the child a route to add information after the appointment. They may notice a symptom only when the questioning has stopped, or communicate more clearly through a message, drawing or familiar adult. Ask the service how to provide a relevant update and whether it changes the review plan.

Do not treat a child's inconsistent description as proof that nothing hurts. Location and intensity can be difficult to identify, and symptoms may genuinely move or come and go. Record their words as given, alongside timing and observable changes. A clinician can weigh that information without the family translating it into certainty.

Close the loop after the appointment

Write down what was examined, the clinician's working explanation, any treatment or test, and the review point. Share only the necessary actions with school and other carers. If a medicine is started, record the intended benefit, timing, possible adverse effects discussed and who should be contacted with a concern.

Continue the same small set of observations rather than creating a new tracking system every day. A stable record shows whether sleep, movement, intake, bowel pattern or distress returns towards baseline. If the child improves, note when and after what intervention without claiming certainty about the cause.

When a referral or result does not arrive, contact the named service and document the attempt. When advice from two professionals conflicts, ask the clinician responsible for the relevant condition to reconcile it. Families should not be left to choose between incompatible instructions about food, medicine, movement or toileting.

If the agreed review point passes and the child remains changed, return with the updated timeline. Persistence is new clinical information, even when the first examination was reassuring.

Avoid replacing one shortcut with another

“Behaviour is communication” is a useful prompt, not a diagnostic formula. A behaviour can relate to pain, fear, communication, sensory overload, learning history, mental health, an unsafe situation or several factors at once.

Do not repeatedly search for hidden illness after appropriate assessment while ignoring a clear environmental harm or emotional crisis. Equally, do not accept autism, ADHD, anxiety or puberty as a complete explanation for a new physical change without reasonable assessment.

The aim is not to prove that behaviour was medical. It is to make sure the child's body receives the same careful attention it would receive if they could describe every symptom conventionally.

Keep the urgent boundary visible

Use emergency help for breathing difficulty, collapse, severe injury, immediate danger or a child who is difficult to wake. Seek urgent clinical advice for severe or rapidly worsening pain, persistent vomiting, dehydration, a stiff neck with illness, a non-blanching rash, sudden weakness, blood, acute testicular pain or serious neurological change.

When uncertain, use current NHS urgent-care guidance for the symptom and tell the service about communication differences. Do not wait for behaviour to become more dramatic before acting on a serious physical sign.

You know your child's ordinary patterns. That knowledge is clinically useful when it is translated into dates, body signs and lost function. Bring the baseline, show the change and leave with a plan for what happens next.

Footnotes

1. NICE QS51 says assessment of behaviour that challenges in autistic people should consider physical health, mental health and environmental triggers, including pain and gastrointestinal conditions. ↩

2. NICE CG99 lists observable stool, pain, withholding, appetite, abdominal and overflow features used in assessment of childhood constipation. ↩

3. NICE CG170 includes physical discomfort, medication, sleep pattern and environmental factors in assessment of sleep problems in autistic children and young people. ↩