Inclusion Criteria:  female gender, the presence of rectorectal or rectoanal intussusception as main cause of ODS, confirmed by defecography, type of operation performed (STARR or LVR), ODS score > 14 [17] PACQoL >32 [18] ODS symptoms for at least 12 months prior to enrollment Failure of at least 6 months of medical therapy  Exclusion Criteria:  male gender, severe fecal incontinence (CCS score>6, Maximum Resting Pressure at rectal manometry < 50 mmHg), combined procedures previous surgery on rectum or anus for cancer or rectal prolapse, inflammatory bowel disease, other type of surgery to relieve ODS pregnancy, anismus or dissinergic defecation full-thickness prolapse stress urinary incontinence associated histerocele or cystocele associated (since we usually correct both defects in the same surgical procedure) prior pelvic radiotherapy slow transit constipation defined as ≤ 2 bowel movements per week, any psychiatric diseases.