An analytical toilet is disclosed. The toilet includes a bowl for receiving excreta, a mechanism that uses a consumable for analyzing a sample of excreta, a storage structure for storing the consumable, a sensor that detects at least one property of the consumable, and a processor that generates an alert when the property is outside a predetermined parameter. The property the sensor detects can be used to determine at least one of the identity of the consumable, the quantity or supply of the consumable, or a property related to the suitability of the consumable.