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.

Inclusion Criteria:

• Clinical suspicion of rumination syndrome and/or supra-gastric belching.
• Sexually active women of child bearing potential participating in the study must use a medically acceptable form of contraception. Medically acceptable forms of contraception include oral contraceptives, injectable or implantable methods, intrauterine devices, or properly used barrier contraception.
• 18 to 75 years old.
• Subjects must be capable of understanding and be willing to provide signed and dated written voluntary informed consent before any protocol-specific screening procedures are performed.

Exclusion Criteria:

• Systemic diseases, known to affect esophageal motility.
• Surgery in thorax or in the upper part of the abdomen.
• Treatment with baclofen prior to the start of the study.
• Significant neurological, respiratory, hepatic, renal, haematological, cardiovascular, metabolic or gastrointestinal cerebrovascular disease as judged by the investigator.
• Pregnancy or breast feeding.
• History of poor compliance. History of/or current psychiatric illness that would interfere with ability to comply with protocol requirements or give informed consent. (well-controlled depression is allowed).
• History of alcohol or drug abuse that would interfere with ability to comply with protocol requirements.