 Patients with fecal incontinence after obstetric anal sphincter rupture will be included. After inclusion, they will be offered 3 months of pelvic floor muscle training. If the patients after completion of pelvic floor muscle training still suffer from fecal incontinence, the patients will be offered treatment with autologous muscle fiber injection into the anal sphincter. The patients will be followed one year after the injection. The autologous muscle fibers are harvested at the patients leg muscle, cut into small pieces and injected into the anal sphincter. A small part of the fibers are used for analysing number of muscle stem cells and thereby the regenerative potential of the sample. 