We all dread diarrhea. But when the patient is your infant or toddler, diarrhea can range from a minor annoyance to a medical emergency. The stools of healthy breast- or formula-fed infants usually have the consistency of oatmeal or cream of wheat, according to the American Academy of Pediatrics (AAP). When diarrhea occurs, the stools become frequent and watery.

The cause can be viruses, bacteria, parasites, or antibiotics. Chronic diarrhea with blood in the stools, listlessness, and weight loss can indicate a severe illness.

Usually, diarrhea lasts several days. Its most serious side effect is dehydration, says Paul Melinkovich, M.D., a pediatrician in Denver. Children need plenty of fluids to replace what they're losing through illness.

Know the signs
Signs of dehydration in infants and young children include a drastic decrease in wet diapers over a 24-hour period, dry mouth, lack of tears when crying, and sunken eyes. Call your health care provider if your child shows any of the signs of dehydration.

To replace the body fluids that are lost with diarrhea, children should drink glucose-electrolyte solutions (for example, Pedialyte or Infalyte), the AAP says. These fluids have the right balance of water, sugar, and salts, and some are available as popsicles. Avoid caffeine, milk products, and foods that are greasy, high in fiber, or very sweet, because they can make diarrhea worse. Avoid just plain water. If breastfeeding, continue to do so.

The U.S. Food and Drug Administration says that loperamide should NOT be used for infants younger than 24 months or without consulting your pediatrician.

You should call the doctor if blood, mucus, or pus is present in stools; if your child has a fever of 102 degrees or higher, diarrhea for more than three days, or severe pain in the abdomen or rectum; or if repeated vomiting or signs of dehydration develop.