A very good physician in the area is an Indian woman, and people go to her for gastro-intestinal issues. She said she got her training because the population “lives in filth”, and the water supply is completely contaminated. It gave her the opportunity to study and treat nasty stuff. She did mention the Ganges River in particular.
You don’t live in Ocean County, NJ do you?
There’s an Indian gastroenterologist who practices in this area and she is highly recommended.