The leading edge of the intussusceptum may be located at 6–8 cm or at 15–18 cm from the anal verge. This proved an older theory from the 18th century by John Hunter and Albrecht von Haller that this condition is essentially a full-thickness rectal intussusception, beginning about 3 inches above the dentate line and protruding externally.Since most patients with rectal prolapse have a long history of constipation, it is thought that prolonged, excessive and repetitive straining during defecation may predispose to rectal prolapse. Since rectal prolapse itself causes functional obstruction, more straining may result from a small prolapse, with increasing damage to the anatomy. This excessive straining may be due to predisposing pelvic floor dysfunction (e.g. obstructed defecation) and anatomical factors:
Abnormally low descent of the peritoneum covering the anterior rectal wall
poor posterior rectal fixation, resulting in loss of posterior fixation of the rectum to the sacral curve
loss of the normal horizontal position of the rectum with lengthening (redundant rectosigmoid) and downward displacement of the sigmoid and rectum
long rectal mesentery
a deep cul-de-sac
levator diastasis
a patulous, weak anal sphincterSome authors question whether these abnormalities are the cause, or secondary to the prolapse. Other predisposing factors/associated conditions include:

pregnancy (although 35% of women who develop rectal prolapse are nulliparous) (have never given birth)
previous surgery (30-50% of females with the condition underwent previous gynecological surgery)
pelvic neuropathies and neurological disease
high gastrointestinal helminth loads (e.g. Whipworm)
COPD
cystic fibrosis The association with uterine prolapse (10-25%) and cystocele (35%) may suggest that there is some underlying abnormality of the pelvic floor that affects multiple pelvic organs.
Lhooq also argues that some who participate in this form of pornography are unaware of the consequences. Terminology
Prolapse refers to "the falling down or slipping of a body part from its usual position or relations". It is derived from the Latin pro- - "forward" + labi - "to slide". "Prolapse". Merriam-Webster Dictionary. Prolapse can refer to many different medical conditions other than rectal prolapse. procidentia has a similar meaning to prolapse, referring to "a sinking or prolapse of an organ or part". It is derived from the Latin procidere - "to fall forward". Procidentia usually refers to uterine prolapse, but rectal procidentia can also be a synonym for rectal prolapse. Intussusception is defined as invagination (infolding), especially referring to "the slipping of a length of intestine into an adjacent portion". It is derived from the Latin intus - "within" and susceptio - "action of undertaking", from suscipere - "to take up". "Intussusception". Merriam-Webster Dictionary. Rectal intussusception is not to be confused with other intussusceptions involving colon or small intestine, which can sometimes be a medical emergency. Rectal intussusception by contrast is not life-threatening. Intussusceptum refers to the proximal section of rectal wall, which telescopes into the lumen of the distal section of rectum (termed the intussuscipiens). What results is 3 layers of rectal wall overlaid. From the lumen outwards, the first layer is the proximal wall of the intussusceptum, the middle is the wall of the intussusceptum folded back on itself, and the outer is the distal rectal wall, the intussuscipiens.