Vomiting, Diarrhea and Dehydration: When to Seek Care

An independent educational resource prepared by Mark M. Simonian, MD, FAAP

Sources checked: August 3, 2026     |     Medical review completed: August 3, 2026

This page is for general education only and does not replace individualized medical advice. This resource does not establish a doctor-patient relationship. For questions about your own child, contact your child's current healthcare professional.

Magnolia Pediatrics, Valley Children's Healthcare

2497 E. Herndon Avenue, Suite 101, Clovis, CA 93611     |     559-538-3070

Vomiting and diarrhea are common, but young children can become dehydrated quickly. Age, alertness, belly pain, urine output, the ability to drink, and the trend over time matter more than the number of vomits or loose stools alone.

Urgent Warning Signs — Check This First

When in doubt about a life-threatening emergency, call 911.

CALL 911 NOW

  • Your child is not breathing normally, turns blue or gray, is limp or unresponsive, cannot be awakened, or you believe your child is in immediate danger

  • A seizure occurs, especially with trouble breathing, blue or gray color, or failure to recover normally afterward

  • Your child shows signs of shock or severe dehydration, such as extreme weakness, confusion, fainting, cold or mottled skin, or inability to stand or stay awake

  • A severe allergic reaction occurs with vomiting plus trouble breathing, swelling of the lips or tongue, widespread hives, collapse, or another serious symptom

GET EMERGENCY MEDICAL CARE NOW

  • Vomiting is green (bile), contains blood, or looks like coffee grounds

  • There is severe, persistent, or localized belly pain; a swollen or rigid abdomen; pain with walking or jumping; or your child wants to lie completely still

  • There is blood in the stool with significant pain, weakness, repeated vomiting, dehydration, or your child looks very ill

  • Poisoning, a medicine overdose, or swallowing a foreign object is possible. Call Poison Control at 1-800-222-1222 for immediate guidance; call 911 for breathing trouble, seizure, unconsciousness, or other life-threatening symptoms

  • Your child cannot keep fluids down and is becoming very sleepy, confused, weak, or is making little or no urine

CONTACT YOUR CHILD'S HEALTHCARE PROFESSIONAL TODAY

  • A baby younger than 3 months has vomited two or more times, has diarrhea, or has a rectal temperature of 100.4°F (38.0°C) or higher. See Fever and Illness: When to Seek Care for the fever pathway

  • Your child has no urine for about 8 hours, very dark urine, a very dry mouth or tongue, no tears when crying, a sunken soft spot in an infant, unusual sleepiness or irritability, dizziness on standing, or increasing weakness

  • Vomiting continues beyond 24 hours, diarrhea is frequent or worsening, your child cannot drink enough to stay hydrated, or symptoms are not improving

  • Your child has a chronic medical condition, diabetes, kidney disease, immune suppression, a feeding problem, or another reason dehydration may be higher risk

  • There is fever with diarrhea, a new rash, jaundice, a swollen abdomen, or ongoing moderate to severe abdominal pain

How to Watch for Dehydration

Urine output and behavior are usually more useful than thirst alone. Check diapers and bathroom trips, and pay attention to whether your child is becoming less alert or less able to drink.

  • Reassuring signs: regular wet diapers or urination, a moist mouth, tears with crying, improving energy, and the ability to take and keep down fluids

  • Concerning signs: fewer wet diapers or bathroom trips, dark urine, dry mouth or tongue, absent tears, a sunken soft spot in an infant, unusual fussiness or sleepiness, weakness, or dizziness when standing

  • A child who is alert, drinking some fluid, and urinating normally is less likely to be significantly dehydrated, but illness can change quickly in infants and young children

Safe Home Care When Your Child Is Alert and Drinking

Home care is reasonable only when there are no warning signs and your child can take fluids. The goal is steady hydration, not making your child drink a large amount all at once.

  • Continue breastfeeding. For babies 6 to 12 months, continue breast milk or formula; if those are not tolerated, ask a healthcare professional about a commercial oral rehydration solution. Do not use plain water as the main fluid for this age group

  • For older children, use a commercial oral rehydration solution when vomiting or diarrhea is more than mild. Offer small, frequent sips from a cup, spoon, syringe, or medicine cup; increase gradually as tolerated

  • After vomiting improves, return to the child's usual age-appropriate foods as tolerated. Do not force food, but do not keep a child on a restricted diet for a prolonged period unless instructed by a healthcare professional

  • Avoid soda, undiluted juice, and other very sugary drinks; they have the wrong balance of sugar and salts and can worsen diarrhea

  • Wash hands well after diaper changes, bathroom use, and before preparing food. Keep your child home from school or child care according to the program's illness policy and your clinician's advice

Medicines and Products

  • Do not give an over-the-counter anti-diarrheal or anti-vomiting medicine unless it has been specifically recommended for your child and this illness by a healthcare professional

  • Do not use leftover prescriptions or antibiotics unless a clinician has directed their use for the current illness

  • For fever or discomfort, use only age-appropriate medicine and follow your child's healthcare professional's directions. See Fever and Illness: When to Seek Care for important fever safety information

What to Have Ready When You Call

  • Your child's age, weight, medical conditions, and current medicines

  • When vomiting or diarrhea started; whether vomit is green, bloody, or coffee-ground-like; and whether there is blood in the stool

  • The last time your child urinated or had a wet diaper; what and how much your child has been able to drink; and whether fluids stay down

  • Temperature and how it was measured; belly pain location; behavior and alertness; and any possible food, medicine, toxin, or foreign-object exposure

Sources and Medical Review

  • HealthyChildren.org (American Academy of Pediatrics), Treating Vomiting: What to Do When Your Child Is Throwing Up: Read source

  • HealthyChildren.org (American Academy of Pediatrics), Drinks to Prevent Dehydration When Your Child Is Vomiting: Read source

  • HealthyChildren.org (American Academy of Pediatrics), Diarrhea in Children: What Parents Need to Know: Read source

  • Centers for Disease Control and Prevention, Treatment of Salmonella Infection: Fluids and dehydration: Read source

  • Poison Control, Get Help: Read source