Rectal Prolapse Overview
The term rectum refers tothe lowest 12-15
centimeters of the large intestine. The rectum is located just above the anal
canal. Normally, the rectum is securely attached to the pelvis with the help ofligaments and muscles. This attachment firmly holds the rectum in place. Various factors, such as age, long-term constipation, and the
stress of childbirth, may cause these ligaments and muscles to weaken, which means that the rectum's attachment to the body also weakens. This causes the rectum to prolapse, meaning it slips or falls out of place. Occasionally, large hemorrhoids (large,
swollen veins inside the rectum) may predispose the rectum to prolapse.
Rectal prolapse issimilarto, but not the same as,rectocele,which is a common conditionin women. A rectocele is a prolapsed rectum that can result whenthe backside (or posterior) wall of the vagina prolapses.
In the early stages of rectal prolapse, the rectum becomes poorly attached but stays within the body most of the time. This stage of rectal prolapse is called mucosal prolapse, or partial prolapse, meaning that only the inner lining of the rectum (rectal mucosa) protrudes from the anus. This occurs when the connective tissues within the rectal mucosa loosen and stretch, allowing the tissue to protrude through the anus. When long-term hemorrhoidal disease is the cause, the condition usually does not progress to complete prolapse.Determining if the problem is hemorrhoids or rectal prolapse is important. Hemorrhoids occur commonly, but they rarely cause rectalprolapse.
As the rectum becomes more prolapsed, the ligaments and muscles may weaken to the point that a large portion of the rectum protrudes from the body through the anus. This stage is called complete prolapse, or full-thickness rectal prolapse, and is the most commonly recognized stage of the condition. Initially, the rectum may protrude and retract depending on the person's movements and activities. However, if the disease goes untreated, the rectum may protrude more frequently or even permanently.
Another condition commonly considered a form of prolapsed rectum is called internal intussusception. Its effects on the rectum are similar to those of mucosal prolapse or complete rectal prolapse; however, in internal intussusception, the rectum neither protrudes from the body nor enters the anal canal.
Rectal prolapse is an uncommon disease and primarily affects elderly people. The disease is rare among children. Affected children are usually younger than 3 years. Men develop rectal prolapse much less frequently than women do (80-90%). In the United States, 0.42% of the overall population have rectal prolapse. In people older than 65 years, the prevalence is 1%.
George Lazarou, MD, FACOG
Simmy Bank, MD, MB, ChB
Mary L Windle, PharmD
BS Anand, MD