A method of treating an ailment suffered by a patient using one or more electrodes adjacent spinal column tissue of the patient, comprises delivering electrical modulation energy from the one or more electrodes to the spinal column tissue in accordance with a continuous bi-phasic waveform having a positive phase and a negative phase, thereby modulating the spinal column tissue to treat the ailment. An implantable electrical modulation system, comprises one or more electrical terminals configured for being coupled to one or more modulation leads, output modulation circuitry capable of outputting electrical modulation energy to the electrical terminal(s) in accordance with a continuous bi-phasic waveform, and control circuitry configured for modifying a shape of the continuous bi-phasic waveform, thereby changing the characteristics of the electrical modulation energy outputted to the electrode(s).