The main objective of this study is to evaluate the efficacy of STW5 Iberogast, over a 28-day period, for the treatment of constipation in parkinsonian patients suffering from gastrointestinal disorders.

Gastrointestinal disorders are the most common non-motor symptoms of Parkinson's disease (PD). They affect the entire intestinal tract and include excess saliva stasis (70% of patients), dysphagia (52%), gastroparesis (34-45%), and constipation. Gastroparesis participates in dyspepsia and abdominal pain. Constipation, as defined by the international standards criteria of Rome III, is present in 59% of PD patients and leads to functional impairment in 70% of patients. The mechanism underlying constipation is multifactorial and may include slow transit and defecation disorders secondary to anorectal dysfunction. Bowel disorders are present in the early stage of the disease and usually precede the onset of motor symptoms. They may result from lesions of the enteric nervous system, of the autonomic nervous system, and from probable alterations in gastrointestinal motility controlled by the central nervous system. The STW5 (Iberogast, Steigerwald, Germany) is a herbal agent composed of nine plant extracts, with prokinetic, antispasmodic, prosecretory, anti-inflammatory and anti-oxidant properties. These properties have been demonstrated in animals and in human pathology, in the treatment of dyspepsia and irritable bowel syndrome. It is the only phytotherapeutic agent which efficacy was demonstrated by randomized double-blind trials in these indications. In PD, the STW5 could improve constipation due to its prokinetic effects of the prosecretory enteric neurons. It could also improve dyspepsia and abdominal pain by its antispasmodic properties. We propose to study the efficacy and the safety of STW5 on bowel dysfunction in parkinsonian patients, especially on constipation.

Inclusion Criteria:

• Patient 30 to 80 years
• Parkinson's disease according to the criteria of the United Kingdom Parkinson's Disease Society Brain Bank
• Presence of constipation defined by the Rome III criteria Functional constipation
• Social assured Patient
• Patients with signed consent

Exclusion Criteria:

• Organic Affection colic
• Constipation Drug
• Other neurological disorder Parkinson's disease
• Metabolic disease diabetes collagenoses
• Severe renal or hepatic impairment
• Pregnant or lactating women
• Premenopausal women without contraceptive device effective
• Regular and prolonged use of history (> 12 months) of laxatives irritants
• Use of oral laxative treatment in the two weeks before the start of treatment, and refusal to stop these treatment during the course of the study
• Taking treatment antabuse
• Cognitive impairment compromising understanding or application instructions
• Patient already included in a research protocol
• Minors
• Nobody protected by law