According to the criteria of Rome IV, 86 patients diagnosed from chronic constipation will be enrolled by up to ten centers.~The study includes 2 visits at the site center and 1 by phone call.~V-1 (eligibility assessment / screening visit):~Collection of written informed consent~Physical examination, including measurement of anthropometric parameters and vital signs (height, weight, diastolic / systolic pressure, heart rate)~Diagnosis according to Rome IV criteria of chronic functional constipation~Blood tests: glycemia, creatinine, complete blood count with formula, ALT, AST, ALP, calcium, potassium, sodium, C reactive protein, total bilirubin. Urinalysis.~Performing a colonoscopy for patients aged> 50 who have not had one performed in the last 5 years.~Guideline for daily diary to collect the number and the consistency of the evacuations, and whether or not they occur with effort~Recording of adverse events and concomitant therapies~V0 (confirmation of possession of selection criteria):~Physical examination, including measurement of anthropometric parameters and vital signs (height, weight, diastolic / systolic pressure, heart rate)~Randomization 1:1 to Sollievo Fisiolax or Placebo~Blood and fecal sample collection for the evaluations of the exploratory objectives~Compliance of the daily diary~Administration of questionnaires: Gastrointestinal Quality of Life Index (GIQLI), PAC-SYM~Any changes in concomitant therapies and any adverse events will be recorded.~V1 (end of treatment or discontinuation before study / treatment time; 4 weeks after V0):~Physical examination, including measurement of anthropometric parameters and vital signs (height, weight, diastolic / systolic pressure, heart rate)~Returned the Investigational product~Blood and fecal sample collection for the evaluations of the exploratory objectives.~Blood tests: glycemia, creatinine, complete blood count with formula, ALT, AST, ALP, calcium, potassium, sodium, C reactive protein, total bilirubin. Urinalysis.~Blood sampling for the screening of HIV, HCV, HBV and TPHA~Check of daily diary~Administration of questionnaires: Gastrointestinal Quality of Life Index (GIQLI), PAC-SYM~Any changes in concomitant therapies and any adverse events will be recorded
This is a multi-center, randomized, double-blinded placebo controlled trial to evaluate the efficacy and safety of the substance-based medical device (Sollievo Fisiolax) in the treatment of Chronic Constipation.~Treatment period for each patient is 28 days.