Diarrhea diseases are caused by so many agents including viruses , bacteria and parasites. The parasites belong to the Kingdom Protoctista and they are unicellular so they always need water to survive. When the water for domestic use is contaminated and one with compromised immune system consumes it, the disease then shows in that person. The disease is spread from person to by any of the following agents , wild and domesticated animals, persons suffering from the disease, wild and domesticated birds etc through water and food. It is characterized by abdominal cramps, putrefied watery faeces, headache, vomiting, fever etc. Giardia infection can be treated but there is no treatment for Cryptosporidium infection and this therefore calls for prevention to save people from the discomfort of having the infection. This book covers all you need to know about these two parasites.