What Are the Causes of Vomiting & Diarrhea in Children?

Vomiting and diarrhea in children may cause dehydration.
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When your child becomes ill and begins to vomit or has watery stools, it usually indicates a viral, bacterial or parasitical problem. Because children become easily dehydrated during bouts of vomiting and diarrhea, it is important to identify the cause in order to provide the most effective treatment against the illness and its symptoms.


Viral gastroenteritis is the term used for inflammation of the gastrointestinal tract that is caused by a virus. This inflammation is conducive to vomiting, diarrhea and nausea in addition to fever, headache and chills. While adults generally are affected only by caliciviruses, children may be infected by three more main viruses including astrovirus, adenovirus and rotavirus, which is the most common cause of viral gastroenteritis in children under the age of five. Most viruses pass through the body within 48 hours, though some can take up to 10 days to clear up. All are highly contagious.

Food Poisoning

Food poisoning occurs when you eat food that is infected with bacteria or toxins. These may grow in leftovers and other foods, even when placed in the refrigerator. Fresh foods, such as raw vegetables and meats, also may cause food poisoning in both adults and children if they are not properly washed or cooked. Among the most common causes for food poisoning are salmonella and e. coli. Vomiting and diarrhea may be accompanied by stomach cramps, nausea and fever. Though most food poisoning cases do not require treatment, high fevers and dehydration warrant a visit to the doctor or emergency room.


A child who is vomiting or experiencing diarrhea may be infected with intestinal parasites. They live inside the digestive tract and can cause diarrhea, vomiting, bloating, weight loss, bloody stools and an itch around the rectum. There are two main types of internal parasites--protozoa and worms. Children acquire parasites when they come in contact with infected fecal matter in soil, foods and water. If you suspect your child has parasites, visit the pediatrician's office for a stool test. The doctor can prescribe an effective treatment.