It turned out that he had Giardia. We now even put Lysol while cleaning the house. Children are more likely than adults to be infected. Day care centers are often significant reservoirs of infection. Dogs may be carriers of the organism.
Water is often a source of epidemics.
The usual levels of chlorine used to purify water are insufficient to eradicate the parasite. Water filtration is required. Cyst excretion is irregular. Hence, several stool specimens may be required to diagnose Giardia in asymptomatic carriers. At times,diagnosis even requires small bowel biopsy.