Diarrhea and Infants

The central concern with diarrhea and infants is the possibility of dehydration from loss of body fluids. Treatment is aimed at preventing dehydration.


Dr. Greene, my baby has been having 4 runny poops each day for the last 5 days (she normally goes once a day). Is this diarrhea? How do you tell diarrhea in a baby? If it is, what should I do?
Bob - Walnut Creek, California

Dr. Greene's Answer

Normal baby stool can look a lot like an adult’s diarrheal stool. Healthy baby poop is often soft and runny, and (especially in the first month) quite frequent. One 2-week-old with 10 runny stools a day may be perfectly healthy, while another 4-month-old with 3 stools a day, all firmer than the other baby’s, may have diarrhea. So how can a parent tell if their child’s stool is normal or considered diarrhea?

Look for a sudden increase in the frequency of the stools. Each baby has her own stool frequency pattern that changes slowly over time. If it changes noticeably within only a few days, she may have diarrhea. Any baby who has more than one stool per feeding should also be suspected of having diarrhea, even if this isn’t a sudden change. Also look for a sudden increase in the water content of the stool. Other signs of illness in your baby, such as poor feeding, a newly congested nose or a new fever, make the diagnosis of diarrhea more likely.

What Causes Diarrhea in Babies?

Diarrhea in babies can be caused by a change in diet (including, sometimes, a change in mother’s diet if the baby is breast-fed), by infection, by antibiotic use, or by a number of rare diseases. Each year there are about one billion cases of diarrhea in children worldwide. In most cases (more than 990 million of them) the diarrhea will resolve by itself within a week or so. Still, more than 3 million young children die each year from diarrhea (about 400-500 in the United States).

Treating Diarrhea in Babies

The central concern with diarrhea is the possibility of dehydration from loss of body fluids. Treatment is aimed at preventing dehydration, the real culprit. Most children with diarrhea can be treated safely at home.

If your baby is breast-fed, don’t stop. Breast feeding helps prevent diarrhea (making diarrhea only half as likely); it also speeds recovery and helps prevent hospitalization (Journal of Pediatrics, May 1996; Pediatrics, April 2007). If your baby still seems thirsty after or between nursing sessions, you can supplement with an oral rehydration solution (Pedialyte is the most well known, but other brands are also effective. Children in my practice seem to prefer the taste of grape-flavored KaoLectrolyte — chilled). Do not try to make your own electrolyte solution at home, as the commercially available solutions are specially formulated to meet your baby’s electrolyte needs.

If your baby is formula-fed, you might want to switch to a soy-based formula while the diarrhea lasts. A soy formula containing fiber, such as Isomil DF, can be tried if your baby is at least 6 months old and may potentially be more effective at slowing down the stools (Clinical Pediatrics, March 1997; Pediatrics, January 1998). Do not dilute the formula. As with breast-fed babies, supplementation with an oral rehydration solution can help replenish the fluids and electrolytes that have been lost in the diarrheal stools.

If your baby is already big enough to be taking solid foods, then carrots, rice cereal, bananas, potatoes, and applesauce can help slow down the stools. Avoid fruit juices, peas, pears, peaches, plums, prunes and apricots until the stools are back to normal, which should be within a week or so.

What if it Lasts “Too” Long?

If the diarrhea lasts longer than a week, or is accompanied by more than 72 hours of fever, get in touch with your pediatrician. Contact your pediatrician right away, however, if your baby won’t drink or appears to be getting dehydrated (dry mouth, crying without tears, sunken soft spot, lethargic, or going 8 hours without producing urine) or if your baby is under 3 months and has diarrhea with a fever. Vomiting for 24 hours, 8 stools in 8 hours, or the presence of blood, mucus, or pus in the stool should also prompt a call to your pediatrician.

So far we’ve been talking about poop. One final thought —

Don’t forget your baby’s bottom. Stool normally contains some of the enzymes that help us digest our food. When stool travels through the intestines more quickly, not only is there more poop, but the poop contains more of these enzymes, which can then start to “digest” the soft skin of your baby’s bottom. Frequent diaper changes, rinsing the bottom with water, air drying, and protective ointments and creams, such as Desitin, can be a real help. Cut down on baby wipes during diarrhea.


During diarrhea, most parents are focused on the frequent, runny poops. Most doctors are focused on the possibility of dehydration. From your baby’s point of view, however, the burning irritation of the diaper rash may be the most pressing issue.

Did you find this article helpful? Still need more information? Let us know in the comments below.

Last medical review on: January 13, 2015
About the Author
Photo of Alan Greene MD
Dr. Greene is a practicing physician, author, national and international TEDx speaker, and global health advocate. He is a graduate of Princeton University and University of California San Francisco.
Get Dr. Greene's Wellness RecommendationsSignup now to get Dr. Greene's healing philosophy, insight into medical trends, parenting tips, seasonal highlights, and health news delivered to your inbox every month.