Provided are stomach simulating devices and methods for simulating a stomach. Stomach simulating devices can comprise a bag-shaped conduit, a mechanical constrictor, and a valve. The conduit can have a body portion, a first diameter at an inlet portion, and a second diameter at an outlet portion, wherein the first diameter at the inlet portion is greater than the second diameter at the outlet portion, the body portion is located between the inlet portion and the outlet portion, and at least a portion of the conduit is curved in a direction from the inlet portion the outlet portion. The mechanical constrictor can he configured to constrict at least a portion of the body portion of the conduit. The valve can be configured to at least partially close a portion of the conduit closer to the outlet portion than the inlet portion of the conduit.