The child then has trouble digesting lactose when he or she drinks milk products. This produces watery diarrhea. This condition is only temporary. Lactose intolerance is caused by a lack of lactase. In young children, temporary lactose intolerance may follow a stomach virus.
Persons can prevent the symptoms by avoiding foods high in milk content.
Lactose may be better tolerated if it is eaten with other foods. In most cases, such tests are not required. If a person's symptoms are felt to be due to lactose intolerance, then milk and milk products can be eliminated from the diet for a period of time. If the symptoms go away, then lactose-containing foods should be added back into the diet to be sure that lactose was the culprit. In most cases, there are no long-term effects.