Diarrhea in Babies: Watching for Dehydration

Diarrhea in a baby usually means stools have become noticeably more watery or frequent than their usual pattern. Breast milk stools can already be loose, so one soft diaper alone does not establish a stomach infection. Look at the change alongside feeding, vomiting, urine output and how alert your baby is.

Babies can lose fluid quickly. Seek advice early if you are worried, especially for a baby under six months or one born prematurely.

Check hydration from the start

Notice whether your baby is taking milk and producing their usual wet diapers. Fewer wet diapers, a dry mouth, sunken eyes or unusual tiredness can suggest dehydration. Do not wait for every sign to appear. Our guide to dehydration in young children explains why a change from the usual pattern matters.

Ask for urgent medical advice if feeding falls, your baby stops taking milk, or vomiting prevents fluids staying down. Diarrhea with blood also needs urgent assessment. A baby under three months with a temperature of 38°C or above needs urgent care.

Get emergency help for green vomit, severe abdominal pain, breathing difficulty, or a baby who is floppy, difficult to wake or not responding normally.

Continue milk feeds unless given a specific treatment plan

For a baby being cared for at home without clinical dehydration, continue breastfeeding or normal infant formula. Smaller, more frequent feeds may be easier if your baby is vomiting. Keep formula at its normal strength. Diluting it is not a safe way to replace fluid losses.

Do not replace milk with juice or fizzy drinks. These can worsen diarrhea and do not provide an appropriate balance for rehydration. Ask the clinician about additional fluid for your baby’s age and circumstances rather than relying on a fixed amount from a general article.

If dehydration is diagnosed, the care team may give a structured oral rehydration plan. Breastfeeding continues during rehydration. Do not give solids during the initial rehydration treatment. Follow the care team’s instructions about other fluids and feeds, then resume usual milk and food after rehydration as advised.

Use oral rehydration solution as directed

A clinician may recommend an oral rehydration solution to replace water and salts. Use the advised product and prepare it exactly as directed. Do not make it more concentrated, mix it into milk or improvise a salt and sugar recipe.

Ask how much to offer, how often and what to do if your baby vomits or refuses it. Small, frequent amounts may be part of the plan. Persistent vomiting or worsening dehydration requires reassessment rather than simply continuing the same approach at home.

Do not give a baby medicine to stop diarrhea. Antibiotics are not routine treatment for gastroenteritis; a clinician decides when a specific infection needs them.

Follow the course and the safety advice

Vomiting from a stomach infection often settles before the diarrhea. Seek advice if diarrhea lasts more than seven days or vomiting more than two days, and much sooner for any warning sign or concern about your baby. These time limits are not instructions to wait when feeding or urine output is falling.

For advice about vomit appearance and other causes, see spit up versus vomiting. Tell the clinician about recent travel, sick contacts and any medicines when discussing the illness.

Wash hands with soap and water after diaper changes and before preparing feeds. Clean contaminated surfaces and follow local childcare advice. Children with infectious vomiting or diarrhea generally stay away until at least 48 hours after the last episode; some infections need specific clearance.

If loose stools persist as your child grows, the assessment may change. Toddler diarrhea describes an ongoing pattern that should be reviewed rather than automatically treated as another stomach bug.