Efficacy and Tolerability of Cassia Fistula Plus Senna Alexandrina Miller (Sugar Free) in the Chronic Functional Constipation (CFC).

Inclusion criteria: * Having chronic functional constipation by ROME IIII criteria * Having the majority of the stool as type 1 or 2 by Bristol Stool Scale * Female subjects should be using an effective contraceptive method more than 3 months if they are sexually active and on reproductive stage * ICF signature * Be able to understand and agree to undertake the study procedures * Having no contraindication related to the study drug * To perform all study visits. Exclusion criteria: * Having previous history or current neurological disorder and/or metabolic one * Having constipation caused by previous surgery * Having intestinal obstruction including colon/rectum cancer * Having endocrine disorder as diabetes mellitus * Having Irritable bowel syndrome or inflammatory bowel disease * Having multiple sclerosis * Having Parkinsons disease * Having Hirschsprungs disease and dyssynergy defecation * Continuous treatment with the following: analgesics, anticholinergic (antihistamines, antispasmodics, antidepressants, antipsychotics) iron supplements or aluminum, opiates, antihypertensive, calcium channel blockers and ganglionic blocker * Treatment with any other laxative medication other than the rescue medication during the study * Patients who could not confirm the chronic functional constipation during the phase I study * Pregnancy or breast feeding woman * Abnormal laboratory results, or clinical result that shows significant by the Investigator * Corporeal mass index \> 30 * Patients who have participate in other clinical study within 30 days * Unable to fulfill the questionnaire (diary) * Any condition that makes impossible to the patient in participates by Investigator opinion. The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.