A process for surgical operations on a rectal/haemorrhoidal prolapse comprises stages of realising, in the anal canal, at least a first circular stitching at a first portion of a haemorrhoidal prolapse; realising at least a second circular stitching in a second portion of the haemorrhoidal prolapse, and nearing the first circular stitching and the second circular stitching in order to create a constriction of the haemorrhoidal prolapse. The invention also relates to a device, preferably for actuating the process, which comprises a hollow divaricator (17) having a prevalent development direction along a longitudinal axis (Z) and being insertable in a patient's anal orifice. The device further exhibits a window (29) defining an operational area and creating a communication between a cavity (17b) internal of the divaricator (17) and a portion of haemorrhoidal prolapse. The device further comprises means for opening and closing (31) the window (29).