In Guyana you can get bottled water in the towns. Otherwise boil water or, more easily, add water purification tablets to your water bottle. We did this routinely. We had no upsets whatever from food or water in the villages. Wear boots or robust joggers.
Sandals are useful around villages.
We did not see very much wildlife. In Toka we met up with a very good guide, Tapok, who knew his plants, their medicinal uses and the animals. He is very good value. We had quite a long trip and it was starting to rain so it was time to leave. We only scratched the surface and would dearly like to return.