The most common causes of abnormal appearing stool in children include:

• Change in diet
• Medication side effect
• Infection:
• Viral gastroenteritis
• Bacterial gastroenteritis
• Malabsorption
• Food allergies

Normal Newborn Stool
Newborn stools appear different than those of children and adults. The first stool is normally thick, sticky and may be green-black or yellow in color. This occurs due to the buildup of material in the intestines during pregnancy. Breastfed infants usually have soft, seedy, mustard-colored stools. Eight or ten stools per day are common in a breast-fed infant. Formula-fed infants tend to have thicker, yellow to brown stools. Their stools are usually larger and have more odor than breast-fed babies.

Normal Infant Stool
Older infants will develop other stool changes after starting solid foods. Yellow, orange, green and brown stools are normal. Sometimes, red food dye can cause a red colored stool. By one year of age, stools should resemble those of an older child or adult.