To be certain that the cause of a faeco-oral disease has been correctly diagnosed, identified the infectious agent can only be done using laboratory techniques. However, identification of the infectious agent is not needed for the correct treatment of most cases of children with mild episodes of watery diarrhoea, which is evident in the majority of the faeco-oral diseases you will come across in your work.
For adults, laboratory examination is required to diagnose faeco-oral diseases accurately. You should base your diagnosis on the specific symptoms and signs, for example, whether there is diarrhoea and (if yes) is it watery or bloody, and does it have a foul smell? Is the patient vomiting or complaining of abdominal pain? Does the patient have a fever? If your diagnosis is ascariasis, you can treat the adult patient as described. But if you suspect other types of faeco-oral diseases (e.g. cholera, typhoid fever), refer the patient to the nearest higher level health facility, sending a referral note stating that further diagnosis is needed before specific treatment can begin. How to make or suspect a diagnosis of specific faeco-oral diseases will be discussed later on, when we talk in more detail about types that you may encounter in your community.