Findings from a retrospective study have demonstrated the long-term clinical effectiveness of collagen injection into the internal anal sphincter for the treatment of passive faecal incontinence. Of the 100 patients in the study, 56 patients had an improvement in faecal incontinence score and 68 patients reported a subjective improvement in symptoms over a minimum follow up of 36 months. Of note, ~50% of patients required a repeat injection of collagen, but no morbidity was reported, indicating that the procedure is safe.