- Study 2: to compare the quality of life and anorectal functional outcomes at : 6, 12, 18 and 24 months after intervention (or ileostomy closure) between the two arms (2A and 2B). The anorectal function will be assessed by the validated COREFO questionnaire and the LARS scale. The quality of life will be assessed by the validated questionnaire of quality of life: SF-36. Another objective is to compare the incidence of postoperative complications assessed by the Clavien-Dindo classification and the incidence of anastomotic leakage.