One of the responsible for one of the major cases of corruption that stole millions from the government spent only 1 year and half in jail. That guy stole for more than 12 years. Nobody cares. Second, the people in Brazil do not have, in general, political inclinations.
Faecal samples may be collected for microbiological culture if the child has significant associated abdominal pain or blood in the stool, as a bacterial cause of gastroenteritis is more likely. However these results usually don't alter treatment.
Your doctor will likely diagnose gastroenteritis based on symptoms, a physical exam and sometimes on the presence of similar cases in your community. A rapid stool test can detect rotavirus or norovirus, but there are no quick tests for other viruses that cause gastroenteritis. In some cases, your doctor may have you submit a stool sample to rule out a possible bacterial or parasitic infection.