Epidemiological study design

You are a public health nurse concerned about the number of children in your community with diarrhoeal disease. You want to do an epidemiological study.
1.     Describe the epidemiological study design you will use to assess the number and spread of diarrhoea among this target population and briefly state the rationale for using this design.
2.     Give two advantages and two disadvantages of this study design.
3.     State the purpose(s) of the study.
4.     Write 10 epidemiological related questions you would ask to get the answers for the study.