A dilution and filtration device comprises: a sampling member comprising a suspension collecting chamber having at least one suspension collecting window disposed at a side surface of the suspension collecting chamber a top cap having a through hole at a center portion of the top cap a connecting cylinder disposed at a top end of the sampling member and mounted to the through hole of the top cap such that the connecting cylinder is concentric with the through hole and is rotatable and a specimen tube connected to the top cap and accommodating the sampling member. An apparatus of preparing excrement detection solutions comprising the dilution and filtration device and a method of preparing excrement detection solutions using the dilution and filtration device are also provided.
