An in-vivo sensing device for capturing sensed data of the gastrointestinal tract, or other body lumens or cavities of a patient, and for transmitting the sensed data to a data recorder external to the patient. The in-vivo sensing device has an identifier code associated with it. The sensed data may be transmitted to the data recorder together with the identifier code so that the received sensed data can be correlated with the in-vivo sensing device.