Patients with a clinical suspicion of rumination syndrome and/or supra-gastric belching are randomized into baclofen or placebo for 2 weeks (10mg, tid). thereafter, they undergo a high resolution impedance manometry measurement, were they receive a solid meal, and recordings continue for another hour. Thereafter, they will receive the alternative treatment, after which they will undergo a second high resolution impedance manometry measurement. Patients are asked to fill out questionnaires during the entire study period.