The symptoms shown in children with intestinal parasites include prolonged diarrhea, nausea, dehydration and stomach cramps, states AboutKidsHealth. Children who have parasites may or may not show symptoms of infection. Other parasites such as fleas, lice and mites present themselves through itchy skin.
The two most common intestinal parasites in children are giardia and worms such as pinworms and tapeworms, according to AboutKidsHealth. Children with giardia may show symptoms of watery diarrhea; soft, greasy stool; fatigue; stomach cramps; nausea; and severe weight loss.
Pinworms may or may not cause symptoms. They live in the rectum and climb out at night to lay eggs on the surrounding skin, according to AboutKidsHealth. This can be itchy around the anus, especially at night, and children may not sleep well because of the irritation. Pinworms can be unpleasant, but they do not cause disease.
Tapeworm symptoms can include diarrhea, nausea, dehydration and stomach cramps, reports AboutKidsHealth. Seek medical assistance if a child has diarrhea or nausea that lasts longer than two weeks, or if a child becomes dehydrated. There is a higher risk of picking up parasites when traveling abroad and when drinking water from unknown sources. The best defense against parasites is good hygiene.