The invention relates to a diagnostic system for the simultaneous long-term registration of heart rate variability as well as the pressure value and/or the impedance and, if so desired, further measured values of a patient with a measuring probe system suitable for deriving data for electrocardiogram generation, a catheter for insertion into the esophagus of the patient, the catheter being provided with several measuring probes each for pressure determination and/or for impedance measurement, and, if required, further measuring probes for determining further measured values, a recording apparatus having a voltage source and a plurality of channels for the registration and recording of the measurement data originating from the measuring probes, at least one memory for time-dependent storage of the measurement data and means for data transmission from the measuring probes to the recording apparatus for use in the diagnosis of motility disorders influenced by the autonomic nervous system and the use of this system in the differential diagnosis of motility disorders.