Chronic constipation is a widespread pathology resulting in a very low frequency of evacuation, and defecation can be also very difficult. In addition to colo-rectal cancer or pelvic floor disfunction, stipsi can be determined by low fibre intake. In our experiment, we tested the efficacy of a linseed-based snack on the defecation frequency in a cohort affected by stipsi. Enrolled people received for 21 days a high fibre and linseed-based snack (30 g)-the severity of constipation was evaluated with the Constipation Scoring System (CSS) determined at the beginning and at the end of the experiment. The consumption of this biscuit significantly increased defecation frequency and reduced difficult or incomplete evacuation. As a consequence of this improvement, the CSS was significantly reduced: 9.19 vs. 4.52. No adverse effects, due to the consumption of the tested snack, were observed. © Springer-Verlag Italia 2013.