New parents learn early on that a baby’s bowel movements change dramatically but predictably. The thick, black, tar-like stools seen on day one transition to thin, mustard yellow, seedy stools by day five. Because a baby’s stool continues to change in texture, color, and odor depending on the baby’s age and diet, many parents worry if they will recognize diarrhea should it occur.

Most babies have the occasional loose bowel movement, which is normal and seldom a cause for concern. However, if there is a sudden increase in the number of loose bowel movements, or if your baby’s stool suddenly becomes larger, looser, and more frequent, she may have diarrhea. This could be diet-related; it could also be caused by intestinal infection (such as a virus, bacteria, or parasite), food allergy, or food poisoning.

The best way to manage diarrhea is to prevent it. Prevention starts with frequent handwashing for your baby and her caregivers—especially before and after eating and after changing diapers or using the toilet. Toys that your baby puts in her mouth should be routinely cleaned, since bacteria and viruses that cause diarrhea can be spread through contact with contaminated objects.

Managing dehydration
Since diarrhea can cause your baby to lose fluid and electrolytes, diarrhea treatment often targets preventing dehydration. When your baby loses more fluid than she takes in, dehydration occurs. It can happen quickly—within a day or two—and it can be very dangerous for babies, especially newborns.

The first signs of dehydration typically include fewer wet and poopy diapers, irritability, and dry eyes, mouth, and tongue. Sunken eyes and less elastic skin (slow to return to normal after being pinched) are signs of moderate dehydration. The soft spots (fontanelles) on your baby’s head may also appear sunken. Signs of severe dehydration include the worsening of early symptoms, crying without tears, rapid breathing, drowsiness, weakness, and loss of consciousness.

Call your child’s health care provider at the first sign of dehydration, especially if your child is younger than 6 months of age, has a rectal temperature of 100.4 degrees F or higher, has abdominal pain, has blood or pus in her stools (which may be black, white, or red), is very weak, or is vomiting.

Babies with moderate or severe dehydration may require intravenous (IV) fluids. Quick medical attention is especially important since dehydration makes it increasingly difficult to insert IV needles into babies’ small veins.

Treating diarrhea
Contact your baby’s health care provider before beginning any diarrhea treatment. Anti-diarrhea medications, including those available over the counter (without a prescription), can have serious side effects. Although the current wisdom is generally to allow diarrhea to run its course while keeping the baby hydrated, your baby may need a prescription, such as an antibiotic (for a bacterial infection) or an antiparasitic (for a parasite infection). In addition, your baby’s doctor may recommend an oral rehydration solution (such as Pedialyte), to replace lost fluid and electrolytes.

In the past, babies and young children were put on a special diet of bananas, rice, applesauce, and toast (BRAT) until the diarrhea stopped. Experts, today, feel the BRAT diet is too restrictive. Instead, parents are told to add starchy foods such as dried cereals, bread, crackers, noodles, mashed potatoes, and rice to their child’s regular diet, and to avoid fatty foods and sugary foods especially fruit juices and soft drinks.

Children over 12 months old can be given probiotics. Probiotics stimulate the growth of healthy bacteria (Lactobacilli) in the GI tract. Yogurt (2–6 ounces or 60–180 milliliters twice a day) is the easiest source of probiotics.

Breastfed babies should continue to breastfeed even more often than before. Breast milk provides much-needed fluids and nutrients, and contains infection-fighting ingredients. Babies who are formula-fed should continue to formula-feed, unless the baby’s doctor recommends giving her an oral rehydration solution.

Remember that breastfed babies normally have loose, frequent stools. To confirm that your baby has diarrhea, watch for mucus or blood in the stool, stool with an unusually foul odor, or a sudden increase in the number of stools. Watch, too, for the signs of illness and dehydration listed above.

Weigh in
Weighing your child can also help you decide if you need to contact your child’s doctor. As a general rule, if there is little or no weight loss, and your child is active and alert, you can safely monitor her progress at home. However, once your child loses 5 percent of her body weight, a sign of mild to moderate dehydration, it’s time to call for help. Parents should also know that rapid weight loss (occurring in a single day) is more concerning than weight loss that occurs over several days. A 10 percent weight loss, regardless of how quickly the weight is lost, is a sign of serious dehydration and requires immediate medical attention. Also, contact your child’s health care provider if symptoms worsen or the diarrhea lasts more than two weeks.

Additional information about infants and diarrhea is available from the American Academy of Pediatrics (AAP). More information about the use of oral rehydration solution can be found here.