Objective: evaluation of therapeutic effect of Descurainia sophia (L.) seeds on clinical symptoms of functional constipation in adults Study design: single-center clinical trial Study population: patients with chronic constipation referred to the gastroenterology clinic: Shariat Panahi clinic, School of Traditional Medicine, Traditional Medicine and Materia Medica Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Main inclusion criteria: adult patients with chronic constipation who fulfilled inclusion criteria ROMIII for chronic functional constipation, and has no sever disease in liver, kidney and cardiovascular systems and announced their agreement to participate in the program by signing a voluntary and informed consent. Main exclusion criteria: Lack of durability of the above conditions; Unwillingness to continue participation in the study; Drug side effects or other threatening events. Sample size: 35 people Intervention Study: A warm syrup of Descurainia sophia (L.) seeds and sugar at fasting once daily