This project aims to offer autologous muscle-derived progenitor cell injection as an efficient mini-invasive surgical therapy that would be simple for the patient and could be used in a majority of cases, including in young women in the post-partum. This approach may provide efficient tissue repair of the striated anal sphincter which is not permitted by existing therapies. This innovative therapy may ultimately be proposed after failure of the common treatments and before an high-risk invasive surgical intervention. Besides, injection of muscle-derived progenitor cells in animals has shown very encouraging results of the sphincter function assessed ex vivo. Hence, a high benefit may be expected with this approach.