This is a 2-arm, parallel-group active- and placebo-controlled, double-blind randomised study, stratified by gender and with a hybrid crossover group design, to compare treatment with prucalopride 2 mg/day (intended therapeutic dose) and prucalopride 10 mg/day (supratherapeutic dose) with placebo. A single oral dose of 400 mg moxifloxacin is included as a positive control in terms of the effect on cardiac repolarisation.