to pass through the gastro esophageal junction while an objective is to maintain the les in a normally constricted state so as to reduce reflux it is obviously important to permit swallowing following food or drink intake and sensor or sensors 37 provide the feedback control to enable this referring now to fig2 there is shown a block diagram of an implantable stimulus generator device for use with the system of this invention the device may suitably be a medtronic model itrel iii pulse generator or a modification thereof the device is battery powered in a well known manner as illustrated the device 30 has a pulse generator circuit 40 for generating a train of stimulus pulses the rate of pulse generation is variable and is controlled by control block 42 block 42 preferably contains a microprocessor and associated built in memory as well as requisite timing circuits the microprocessor control inter connects with memory 43 which can store a record of data obtained by the device provide ram routines etc a transceiver 46 provides telemetric communication with an external programmer 48 in a fashion well known in the pacemaker art for receiving new instructions data for programming the pulse parameters etc thus the rate amplitude duty cycle etc of the pulse train provided by generator 40 can by programmed externally additionally the programmer can be used by the patient to stop or turn off operation of the stimulator which might be useful in certain circumstances such as sickness the pulses generated by circuit 40.