Last updated: October 2026. This article is for general information and is not a substitute for personalised advice from your doctor, health visitor, or paediatrician. See our Editorial Policy.
Quick answer: In late September 2026 the American Academy of Pediatrics (AAP) published its first update since 2011 to its guideline on urinary tract infections (UTIs) in young children. It now covers ages 8 days to 5 years and encourages evaluation for a possible UTI within 72 hours for children aged 2 months to 5 years who have a fever with no identified cause or who have urinary symptoms. In babies and toddlers up to age 2, a UTI may cause few signs other than fever, so call your pediatrician about an unexplained fever. For most children, the AAP prefers antibiotic courses of 7 days or less. Never treat a suspected UTI at home without a diagnosis.
What changed, and why parents are hearing about it now
On September 28, 2026, the AAP posted its new “Clinical Practice Guideline for the Diagnosis and Treatment of Urinary Tract Infection in Children From 8 Days to 5 Years of Age.” According to HealthyChildren.org, the guideline comes with three technical reports reviewing the evidence on risk factors, diagnosis, treatment, imaging, prevention and outcomes, and all of it appears in the October 2026 issue of Pediatrics. It is the first update since 2011.
The old guideline covered children aged 2 months to 2 years. The new one widens that to 8 days through 5 years. The AAP also says the previous version was retired in 2021 because it improperly used race as a biological factor when calculating risk; race is not a risk factor in the update.
How common are UTIs in young children?
The AAP’s parent news page calls UTIs one of the most common bacterial infections in babies and children, affecting up to 7% of infants who have a fever. HealthDay, reporting on the guideline and citing the AAP, adds that by age 6 up to 7% of girls and 2% of boys will have a UTI, and that in about 30% of cases the infection comes back. These figures describe different groups (febrile infants versus all children by age 6), so they are not contradictory.
UTIs matter because, as HealthyChildren.org explains, UTIs in infants and younger children have a greater chance of causing kidney damage than UTIs in older children. Prompt treatment lowers that risk.
UTI symptoms in babies and toddlers
HealthyChildren.org says UTIs in infants and young children up to 2 years old may have few recognizable signs other than a fever. That is why the guideline focuses so much on fever with no obvious explanation.
Signs vary with age and with whether the bladder or kidneys are involved. The AAP lists these for a bladder infection:
- Lower abdominal pain or tenderness
- Pain or burning when peeing, or peeing more often
- Blood in the urine
- Vomiting
- New day or night wetting in a child who was already toilet trained
- A low-grade fever
A kidney infection tends to cause more general abdominal pain and a higher fever, and it may or may not cause frequent or painful urination. HealthyChildren.org also notes that constipation can cause symptoms that look like a UTI, which is one reason a doctor needs to test rather than guess.
The 72-hour rule: when to get a fever checked
The headline change is timing. The AAP’s guidance encourages evaluation for a possible UTI within 72 hours for children aged 2 months to 5 years who have a fever without an identified cause or who have urinary symptoms. It adds that more urgent evaluation may be appropriate for children at higher risk, to help reduce kidney injury and scarring.
Note that some news summaries phrase this more broadly, saying any child aged 2 months to 5 years should be tested within 72 hours of a fever with no apparent cause. The AAP’s own wording is the one above, so use it as your reference and let your pediatrician decide what applies to your child.
In practical terms, HealthyChildren.org says to contact your pediatrician if you think your child may have a UTI, especially for infants, in whom an unexplained high fever may be the only sign. It also advises talking with your pediatrician if an infant has a fever with no other symptoms for more than 3 days. If your child has an obvious other cause for the fever, such as a cold, that is a different situation; see our guide to back-to-school colds and bronchiolitis in babies and toddlers.
How doctors test for a UTI in a child in diapers
Doctors diagnose a UTI using a combination of symptoms and a urine test. For children who are not toilet trained, the AAP’s parent pages describe several ways to collect urine:
- Clean catch: catching pee mid-stream. It takes patience and is easier if the child has not recently had a wet diaper.
- Urine collection bag: an adhesive bag placed over the genital area. Samples can be contaminated by skin bacteria.
- Catheter sample: a thin tube gently slid into the bladder by a health care provider. The AAP says it is not painful, only a little uncomfortable, and has a lower risk of contamination.
HealthyChildren.org says that if a bag or clean-catch sample looks possibly infected, the result should be confirmed with a catheter sample. Collecting urine at home is generally something to do only if your pediatrician asks you to, using their instructions.
Treatment: shorter antibiotic courses
The guideline says shorter antibiotic courses of 7 days or less are preferred for most children with a UTI. Longer courses may be needed for infants, higher-risk children, or those who are not improving as expected, and the length should be tailored to age, severity and response.
If your child is prescribed antibiotics, HealthyChildren.org stresses finishing the full course your doctor prescribes, even if symptoms fade in a few days, because stopping early can let bacteria regrow. Your child’s exact medicine and length of treatment are decisions for their doctor. If the first antibiotic is changed after culture results come back, that is normal.
Recurrent UTIs, constipation and bladder habits
The new guideline puts more emphasis on constipation and bladder-bowel dysfunction as factors that may contribute to repeat UTIs. HealthyChildren.org adds that whether a child needs imaging tests such as an ultrasound depends on age and how many UTIs they have had, and that a child may be referred to a pediatric urologist or nephrologist if tests suggest a structural problem. If your child keeps getting UTIs, ask your pediatrician about stooling and bathroom habits as part of the plan.
What parents can do now
- Take your baby’s or toddler’s temperature with a reliable digital thermometer and note when the fever started, so you can tell your pediatrician how long it has lasted.
- Call your pediatrician for an unexplained fever in an infant instead of waiting it out, and mention any change in feeding, vomiting, irritability or diaper habits.
- Ask what urine collection method your child’s doctor recommends.
- Finish any prescribed antibiotics as directed.
- Ask about constipation if UTIs recur.
For emergencies, such as a very sick-looking baby, call your local emergency number or go to the nearest emergency department.
The bottom line
The AAP’s 2026 update widens UTI guidance to cover children from 8 days to 5 years, encourages evaluation within 72 hours for fever without a clear cause or urinary symptoms, prefers antibiotic courses of 7 days or less for most children, and pays more attention to constipation in recurrent infections. Because babies and toddlers often show few signs besides fever, the most useful thing a parent can do is call early about an unexplained fever and let the doctor test. If you want a printable to keep on the fridge, the New Parent Starter Bundle includes a “when to call the doctor” checklist and a feeding and nappy log.
Sources
- American Academy of Pediatrics, HealthyChildren.org: Updated AAP Guidance on Urinary Tract Infections (UTIs) in Young Children (Sept. 28, 2026)
- American Academy of Pediatrics, HealthyChildren.org: Urinary Tract Infections (UTIs) in Children: Symptoms, Causes, Diagnosis & Treatment (last updated Sept. 28, 2026)
- American Academy of Pediatrics, HealthyChildren.org: How to Collect a Urine Sample From a Baby
- HealthDay via Powers Health: Pediatricians’ Group Updates Guidelines On UTIs In Babies, Kids (Sept. 30, 2026)
- Pediatrics (guideline listing, October 2026 issue): Clinical Practice Guideline for the Diagnosis and Treatment of Urinary Tract Infection in Children From 8 Days to 5 Years of Age. The full text sits behind the journal’s site, so the details above are drawn from the AAP’s own HealthyChildren.org summaries.
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