Why Does My Baby Have Diarrhea?
You’re changing your fourth—or fifth or sixth—explosive diaper of the day, and you’re starting to panic. Is this normal? What’s causing it? When should you call the doctor? Conway Medical Center’s experienced pediatric providers help worried parents figure out what’s causing baby diarrhea, when you can handle it at home, and when you really need to call the doctor.
Concerned about your baby’s diarrhea? CMC Pediatrics provides expert care at four convenient Horry County locations. Call 843-347-8000 to schedule an appointment. For severe symptoms or babies under 3 months, don’t hesitate—seek immediate care or call 9-1-1.
In this article:
What Baby Diarrhea Actually Looks Like
First things first—how do you know if your baby actually has diarrhea? Since baby poop is normally softer than adult poop, it can be tricky to tell.
Normal Newborn Poop:
- Yellow, loose, and seedy texture
- 3-4 poopy diapers daily
- Tiny flecks from breastfeeding are normal
- Softer than cottage cheese
As Babies Grow (4-6 Months):
- Thicker consistency like cottage cheese or applesauce
- Color and frequency vary
Diarrhea Means:
- Suddenly much looser or more watery than usual
- Happening more frequently (3+ extra poopy diapers)
- Lasting through multiple diaper changes
PARENT HINT: One major clue that it’s diarrhea—it overflows out of the diaper. If you’re dealing with blowouts, that’s probably diarrhea.
Common Causes of Diarrhea in Babies
Multiple culprits can trigger those watery diapers. Understanding the cause helps you know what to expect and how long it might last.
Viral Infections (Most Common)
In fact, viruses cause about 70% of diarrhea episodes in babies and young children.
Rotavirus:
- Most serious illness occurs in children under 3 years old
- Watery diarrhea, vomiting, fever
- Highly contagious
- Risk highest in winter and spring
- GOOD NEWS: Rotavirus vaccine (given at 2 and 4 months) is 74-96% effective at preventing serious illness
Norovirus:
- Extremely contagious
- Spreads easily in daycares and group settings
- Usually causes vomiting along with diarrhea
IMPORTANT NOTE: Viral diarrhea typically lasts 5-7 days. However, there’s no specific medicine for viral gastroenteritis—your baby’s immune system fights it off while you focus on keeping them hydrated.
Bacterial Infections
Bacteria account for about 10-20% of diarrhea cases.
Common Bacterial Culprits:
- Salmonella (from contaminated food or contact with infected person)
- E. coli (undercooked food, contaminated water)
- Campylobacter (more common after age 5)
When Bacteria Are the Cause:
- Diarrhea may contain mucus or blood
- Often accompanied by fever
- May require antibiotics (your pediatrician will decide)
Food-Related Causes
Too Much Juice: Excessive juice (especially apple, pear, or prune juice) can cause diarrhea in babies because the natural sugars pull water into the intestines.
PARENT HINT: The American Academy of Pediatrics recommends NO juice for babies under 12 months, and limited amounts after that.
Food Allergies or Sensitivities:
- Cow’s milk protein allergy
- Soy intolerance
- Introduction of new solid foods
Changes in Diet:
- Starting solid foods
- Switching formula brands
- Changes in breastfeeding mother’s diet
Antibiotic Side Effects
Antibiotics kill bad bacteria but also kill good bacteria in the gut, disrupting the digestive balance and causing diarrhea. Therefore, this affects the baby taking antibiotics OR the breastfeeding mother taking them.
IMPORTANT NOTE: Never stop antibiotics because of diarrhea—complete the full course as prescribed. The diarrhea typically resolves after the antibiotic course ends.
Teething (Controversial)
Many parents swear teething causes diarrhea, but pediatricians debate this connection. If diarrhea occurs during teething, it’s more likely coincidental—babies teethe around the same time they’re exposed to more viruses from increased hand-to-mouth activity.
Home Care That Really Works
Fortunately, most baby diarrhea cases resolve at home within a few days with proper care. Here’s what actually helps.
Keep Them Hydrated (Priority #1)
Babies lose significant water and electrolytes through diarrhea. Dehydration is the biggest danger.
When Breastfeeding Babies:
- Continue breastfeeding on demand
- May need to nurse more frequently
- Breast milk provides hydration, nutrition, and antibodies
For Formula-Fed Babies:
- Continue regular formula—don’t dilute it
- Offer formula more frequently
- Don’t switch formulas unless directed by your pediatrician
When Babies are Eating Solids:
- Continue offering age-appropriate foods
- Starchy foods digest easily (rice cereal, bananas, applesauce)
- Don’t restrict solid foods unless vomiting
PARENT HINT: If your baby is vomiting, let their stomach rest 15-20 minutes after each episode, then offer small amounts of liquid.
Oral Rehydration Solutions
Additionally, for moderate to severe diarrhea, pediatricians often recommend electrolyte solutions like Pedialyte or Infalyte.
How to Use:
- Offer 1 ounce (2 tablespoons) every 30-60 minutes
- Don’t dilute the solution
- Continue throughout the day
- Pedialyte popsicles work great for toddlers
IMPORTANT NOTE: Don’t give sports drinks to young infants—they contain too much sugar and not enough of the right electrolytes for babies.
Protect That Bottom
Frequent watery stools cause painful diaper rash quickly.
Prevention Strategies:
- Change diapers immediately after bowel movements
- Gently wash with warm water (wipes may sting)
- Pat dry completely before applying new diaper
- Use thick barrier cream (zinc oxide)
- Allow diaper-free time when possible
PARENT HINT: Keep a small spray bottle of warm water and soft cloths by the changing table for gentle cleaning during diarrhea bouts.
What NOT to Do
Don’t give over-the-counter anti-diarrhea medications to babies or young children unless specifically prescribed by your pediatrician. These can be dangerous.
Don’t restrict fluids thinking it will “slow things down”—hydration is critical.
Don’t panic and rush to the ER for every case—most diarrhea resolves at home. (But do know the warning signs below!)
Dehydration Warning Signs Every Parent Must Know
Dehydration is the most dangerous complication of baby diarrhea. Babies can become dangerously dehydrated within 24-48 hours.
Call Your Pediatrician Immediately If You Notice:
Fewer Wet Diapers:
- Fewer than 6 wet diapers in 24 hours
- No wet diaper for 3+ hours in older babies
- Urine is dark yellow instead of pale
Physical Changes:
- Sunken soft spot (fontanelle) on baby’s head
- Sunken eyes or cheeks
- No tears when crying
- Dry mouth and lips
- Skin loses elasticity (when pinched gently, stays “tented”)
Behavioral Changes:
- Excessive sleepiness or lethargy
- Unusual irritability
- Lack of interest in feeding
- Weakness
IMPORTANT NOTE: Babies under 3 months and babies with severe dehydration may need hospital care with IV fluids for a day or two to recover safely.
When to Call the Doctor vs. When to Go to the ER
Knowing when to seek help prevents both unnecessary ER visits AND dangerous delays in care.
Call CMC Pediatrics If:
Your Baby Is Under 3 Months: Call for ANY diarrhea in newborns and young infants—they’re more vulnerable.
Diarrhea Lasts More Than 24 Hours: Especially if accompanied by other symptoms
Mild Dehydration Signs: Fewer wet diapers but baby is still alert and feeding
Persistent Symptoms: Diarrhea continues beyond 5-7 days
Other Concerning Symptoms:
- Fever of 100.4°F or higher (under 3 months)
- Fever of 102°F or higher (any age)
- Unusual fussiness or behavior
- Decreased appetite
PARENT HINT: It’s always okay to call your pediatrician with questions. They’d rather hear from worried parents than have you second-guess serious symptoms.
Go to CMC Emergency Department or Call 911 If:
Severe Dehydration Signs:
- No wet diapers for 6+ hours
- Extremely lethargic or unresponsive
- Sunken fontanelle
- No tears, very dry mouth
Dangerous Stool Appearance:
- Black or tarry stools (may indicate internal bleeding)
- Blood in stool (more than small streaks)
- White or clay-colored stools (liver/gallbladder issue)
- Pus in stool
Severe Symptoms:
- Uncontrollable vomiting preventing any fluid intake
- Severe abdominal pain
- High fever with extreme lethargy
- Signs of shock (pale, clammy skin, rapid breathing)
IMPORTANT NOTE: Trust your parental instincts. If something feels very wrong, seek emergency care immediately. You know your baby best.
Expert Pediatric Care at CMC
Conway Medical Center provides comprehensive pediatric care from routine checkups to urgent concerns, with providers experienced in managing everything from minor illnesses to serious conditions.
CMC Pediatrics: Four Convenient Locations
CMC Pediatrics includes 15 experienced board-certified pediatricians, pediatric specialists, and nurse practitioners dedicated to providing expert care for children from birth through adolescence.
CMC Pediatrics Locations:
Conway: 2376 Cypress Circle
Conway, SC 29526
Carolina Forest: 270 Swamp Fox Court
Myrtle Beach, SC 29579
Socastee: 6010 Highway 707
Myrtle Beach, SC 29588
Aynor (CPG Family Medicine): 1028 11th Avenue
Aynor, SC 29511
Call 843-347-8000 to schedule at the location most convenient for you.
CMC Emergency Department: Pediatric Emergency Care
Conway Medical Center has been accredited as an Advanced Pediatric Ready Emergency Department through the National Pediatric Readiness Project (NPRP) in partnership with the South Carolina Department of Public Health. This designation reflects a hospital-wide commitment to meeting rigorous standards in staffing, training, equipment, and protocols—all designed to address the unique needs of children during medical emergencies.
With approximately 8,000 pediatric patients treated in CMC’s Emergency Department each year, this accreditation ensures our community’s youngest patients receive specialized, individualized pediatric care close to home. CMC features a children’s waiting area and dedicated pediatric emergency clinical space designed to create a more comfortable and reassuring environment for young patients and their families.
Location: 300 Singleton Ridge Road
Conway, SC 29526
Available: 24/7/365
For Medical Emergencies: Call 911
Don’t second-guess serious symptoms. Whether your baby needs routine pediatric care at CMC Pediatrics’ four convenient locations or emergency evaluation, expert help is available throughout Horry County. Call 843-347-8000 for Pediatrics. For emergencies, visit CMC Emergency Department or call 911.
Key Takeaways
- Baby diarrhea means suddenly much looser, more watery poops happening 3+ extra times daily, often overflowing diapers—don’t confuse with normal soft baby stool.
- Viruses cause about 70% of baby diarrhea cases, typically lasting 5-7 days with no specific treatment beyond hydration and immune system recovery.
- Continue breastfeeding or regular formula (don’t dilute) more frequently, and consider Pedialyte for moderate-to-severe cases—hydration is the #1 priority.
- Watch for dehydration warning signs: fewer than 6 wet diapers in 24 hours, sunken fontanelle, no tears when crying, excessive sleepiness, or dry mouth.
- Call pediatrician immediately for babies under 3 months with ANY diarrhea, or any baby with blood/black stools, high fever, or dehydration signs.
- Seek emergency care for severe dehydration (no urine for 6+ hours), unresponsive behavior, bloody/black stools, or uncontrollable vomiting preventing fluid intake.
- CMC Pediatrics provides expert care at four Horry County locations (Conway, Carolina Forest, Socastee, Aynor) with 15 board-certified providers—call 843-347-8000.
