An apparatus for treating reflux disease of a human or animal mammal patient. The apparatus comprising an implantable stimulation device (26) adapted to engage with the cardia sphincter of the patient and a control device (56) for controlling the stimulation device to stimulate the cardia sphincter by providing electrical energy pulses for increasing a sphincter tonus so that the cardia closes. The control device is adapted to, in an operational state, cause the stimulation device to stimulate the cardia sphincter with at least two pulse trains. At least some of the pulses within at least one of the pulse trains are separated from each other by a first time break. At least two pulse trains are separated from each other by a second time break and the second time break is longer than the first time break.