Rectal prolapse refers to the downward displacement of the anal canal, rectum, or even the lower end of the sigmoid colon. Prolapse involving only the mucosa is called incomplete prolapse, while prolapse of the entire rectal wall is termed complete prolapse. If the prolapsed part remains within the anal canal or rectum, it is referred to as prolapse or internal intussusception; if it protrudes outside the anus, it is called external prolapse. Rectal prolapse is common in children and the elderly. In children, it is a self-limiting condition that often resolves on its own before the age of 5, so non-surgical treatment is the primary approach. In adults, severe complete rectal prolapse can lead to long-term complications such as pudendal nerve injury, fecal incontinence, ulcers, perianal infections, rectal bleeding, edema of the prolapsed segment, stenosis, and even necrosis. Therefore, surgical treatment is the mainstay for such cases.

bubble_chart Etiology

The factors that can cause rectal prolapse include the following.

(1) Anatomical factors

In children, the curvature of the sacrococcygeal region is shallower than normal, and the rectum is in a vertical position. When intra-abdominal pressure increases, the rectum loses the support of the sacrum and is prone to prolapse. In some adults, the peritoneal reflection in the anterior rectal pouch is lower than normal. When intra-abdominal pressure increases, the intestinal loops directly press on the anterior wall of the rectum, pushing it downward and easily leading to rectal prolapse.

(2) Weakness of the pelvic floor tissues

In the elderly, muscle relaxation, multiple childbirths in women, perineal tears during childbirth, and underdevelopment in young children can all result in hypoplasia or atrophy of the levator ani muscle and pelvic floor fascia, making them unable to support the rectum in its normal position.

Factors such as chronic constipation, chronic diarrhea, difficulty urinating due to prostate enlargement, and chronic cough caused by chronic bronchitis can all lead to rectal prolapse.

bubble_chart Pathogenesis

Currently, there are two theories regarding the occurrence of rectal prolapse. The first is the sliding hernia theory: it suggests that rectal prolapse is a sliding hernia of the peritoneal pouch in the pelvic cavity. Under the pressure of abdominal organs, the peritoneal folds of the pelvic pouch gradually descend, compressing the anterior rectal wall covered by the peritoneum into the rectal ampulla, eventually protruding through the anus. The second is the intussusception theory: normally, the upper end of the rectum is fixed near the sacral promontory. Due to chronic cough, constipation, and other factors that increase intra-abdominal pressure, this fixed point is injured, making intussusception prone to occur at the junction of the sigmoid colon and rectum. Under the continuous influence of increased intra-abdominal pressure, the length of the intestine telescoping into the rectum gradually increases. The alternation of intussusception and its reduction leads to injury of the lateral rectal ligaments and levator ani muscles, progressively worsening the intussusception until it finally protrudes through the anus. Some also believe that these two theories are essentially the same, differing only in degree—the sliding hernia is a form of intussusception that does not involve the entire intestinal wall, whereas the latter is a full-thickness intussusception.

bubble_chart Clinical Manifestations

(1) Partial prolapse (incomplete prolapse)

The prolapsed part is only the mucous membrane of the lower rectum, hence it is also called mucous membrane prolapse. The prolapsed length is 2–3 cm, generally not exceeding 7 cm. The mucosal folds are radial, and the prolapsed part consists of two layers of mucous membrane. There is no sulcus between the prolapsed mucous membrane and the anus.

(2) Complete prolapse

This involves the full-thickness prolapse of the rectum. In severe cases, both the rectum and anal canal may protrude outside the anus. The prolapsed length often exceeds 10 cm, even up to 20 cm, presenting a pagoda shape. The mucosal folds are arranged in a circular pattern, and the prolapsed part consists of two layers of folded intestinal wall, which feels thicker to the touch. There is a peritoneal space between the two layers of intestinal wall.

The onset is slow. In the early stage, a mass may protrude from the anus only during defecation and retract spontaneously afterward. As the condition progresses, due to the lack of contraction in the levator ani and anal sphincter muscles, manual assistance may be required for repositioning. In severe cases, prolapse may occur during coughing, sneezing, exertion, or walking, and repositioning becomes difficult. If not promptly reduced, the prolapsed intestinal segment may develop edema, strangulation, or even risk necrosis. Additionally, there is often a sensation of incomplete bowel movement, anal heaviness, and soreness. Some may experience lower abdominal distension and fullness, pain, frequent urination, etc. Incarceration causes severe pain.

The diagnosis of rectal prolapse is not difficult. When the patient squats and performs a defecation motion, exerting abdominal muscles, the prolapse can be observed. In cases of partial prolapse, a round, red, smooth-surfaced mass can be seen, with the mucous membrane exhibiting "radial" folds and a soft texture, which retracts spontaneously after defecation. In cases of complete prolapse, the prolapsed segment is longer, appearing pagoda-shaped or spherical, with visible annular folds of the rectal mucous membrane on the surface. Digital rectal examination reveals a relaxed and weak sphincter. If the prolapse contains small intestine, borborygmi may sometimes be heard.

Rectal mucosal prolapse must be differentiated from circumferential internal hemorrhoids. Apart from differences in medical history, circumferential internal hemorrhoids present as congested and hypertrophied hemorrhoidal masses in a plum-blossom pattern, prone to bleeding, with depressed normal mucous membrane visible between the hemorrhoidal masses. Digital rectal examination shows strong sphincter contraction, whereas rectal mucosal prolapse presents with relaxation, which is an important distinguishing feature.

The diagnosis of internal rectal prolapse is more challenging and requires defecography for confirmation. However, the condition should be suspected when the patient complains of obstruction in the rectal ampulla and a sensation of incomplete defecation.

bubble_chart Treatment Measures

(1) Non-surgical Treatment

Most cases of rectal prolapse in infants can heal spontaneously, so non-surgical treatment is the primary approach. As the child grows and the curvature of the sacrum develops, the rectal prolapse will gradually disappear. Measures include correcting constipation and establishing good bowel habits. Defecation time should be shortened, and the prolapse should be manually reduced immediately after bowel movements. If the prolapse has been prolonged, leading to congestion and edema, the child should be placed in a prone or lateral position, and manual reduction should be performed promptly by pushing the prolapsed tissue back into the anus. After reduction, a digital rectal examination should be conducted to ensure the prolapsed bowel is repositioned above the sphincter. Following manual reduction, a gauze roll can be used to block the anal area, and the buttocks can be taped together to temporarily seal the anus, preventing recurrence due to crying or increased abdominal pressure. If the condition persists for an extended period without improvement using the above methods, injection therapy may be employed. Method: Inject 5% phenol in vegetable oil into the submucosal layer of the rectum or around the rectum, divided into 4–5 injection sites, with 2 ml per site (total 10 ml). The injection can be administered under direct vision via a proctoscope to adhere the mucosa to the muscular layer, or it can be delivered perianally under digital rectal guidance to fix the rectum to surrounding tissues.

(2) Surgical Treatment

For adults with incomplete prolapse or grade I complete prolapse, if sphincter tone is normal or slightly weak, procedures similar to hemorrhoidectomy or rubber band ligation may be performed, or sclerotherapy may be used. If sphincter relaxation is present, anal encirclement or sphincteroplasty may be considered.

The treatment of complete rectal prolapse in adults is primarily surgical, with four main approaches: transabdominal, transperineal, abdominoperineal, and sacral. There are numerous surgical methods, each with its own advantages, disadvantages, and recurrence rates. No single method is suitable for all patients, and sometimes multiple techniques are required for the same patient. In the past, surgeries focused only on repairing pelvic floor defects, resulting in high recurrence rates. In recent years, research on the intussusception theory of rectal prolapse has led to surgical approaches that target the rectum itself. The following procedures are commonly used today:

1. Rectal Suspension and Fixation

(1) Ripstein Procedure: Through an abdominal incision, the peritoneum on both sides of the rectum is opened, and the posterior rectal wall is freed to the tip of the coccyx, elevating the rectum. A 5 cm-wide Teflon sling is wrapped around the upper rectum and fixed to the presacral fascia and periosteum below the sacral promontory. The edges of the sling are sutured to the anterior and lateral rectal walls without repairing the pelvic floor. Finally, the peritoneal incisions on both sides of the rectum and the abdominal wall layers are closed. The key points of this procedure are elevating the pelvic cul-de-sac and its simplicity, as it does not require bowel resection. Recurrence and mortality rates are relatively low, making it widely used in countries like the U.S. and Australia. However, complications such as fecal impaction obstruction, presacral hemorrhage, stenosis, adhesive small bowel obstruction, infection, and sling slippage may occur. Gorden reviewed 1,111 cases of rectal prolapse treated with the Ripstein procedure, reporting a recurrence rate of 2.3% and a complication rate of 16.6%. Tjandra (1993) treated 169 cases of rectal prolapse over 27 years, performing 185 surgeries, including 142 Ripstein procedures. Postoperative constipation occurred in 42 cases (27 preexisting, 15 new-onset), and fecal obstruction occurred in 7 cases. 35% of patients were dissatisfied with the Ripstein procedure due to persistent bowel dysfunction symptoms (constipation, diarrhea, or alternating constipation and diarrhea). Therefore, he suggested that for patients with constipation, bowel resection with or without fixation is superior to the Ripstein procedure.

(2) Ivalon Sponge Implantation: This procedure was first introduced by Well, hence it is also known as the Well operation or posterior rectopexy. Currently, this method is widely used in the UK to treat adult complete rectal prolapse. Method: The rectum is freed via an abdominal approach to the posterior wall of the anorectal ring, and sometimes the upper half of the lateral rectal ligaments is severed. A semicircular Ivalon sponge sheet is sutured into the sacral concavity using non-absorbable sutures. The rectum is then pulled upward and placed in front of the Ivalon sheet, or simply wrapped around the freed rectum without suturing to the sacrum to avoid presacral bleeding. The Ivalon sponge is sutured to the lateral wall of the rectum, while the anterior wall of the rectum is left open with a gap of about 2–3 cm to prevent narrowing of the intestinal lumen. Finally, the sponge sheet and rectum are covered with the pelvic peritoneum. The advantage of this method lies in the fixation of the rectum to the sacrum, which stiffens the rectum and prevents intussusception, with low mortality and recurrence rates. However, if infection occurs, the sponge sheet becomes a foreign body and may lead to fistula formation. The most significant complication of this procedure is pelvic suppuration caused by the implanted sponge sheet. Preventive measures include: ① thorough preoperative colonic preparation; ② placing antibiotic powder within the implanted sheet; ③ administering high-dose broad-spectrum antibiotics during surgery; ④ ensuring complete hemostasis; and ⑤ avoiding implantation if the rectal wall is accidentally perforated during the procedure. If pelvic infection occurs, the suspended sponge sheet must be removed. Some reports indicate no recurrence of rectal prolapse after removal. Marti (1990) reviewed 688 cases of the Well operation in the literature, with an infection rate of 2.3%, surgical mortality of 1.2%, and recurrence rate of 3.3%.

(3) Suspending the rectum on the sacrum; In the early stage, Orr used two strips of fascia lata from the thigh to fix the rectum to the sacrum, typically twice the length of the prolapse (generally, folding should not exceed five layers). The folds in the intestinal wall must face downward, and sutures should not be placed upward. Each strip is approximately 2 cm wide and 10 cm long. After appropriate mobilization of the rectum, one end of the fascia lata strip is sutured to the elevated anterolateral wall of the rectum, and the other end is fixed to the sacral promontory to achieve suspension. In recent years, it has been advocated to use nylon or silk strips or two strips of fascia taken from the anterior rectus sheath to replace the fascia lata, with good results. There have been two domestic reports on the Orr procedure, totaling 31 cases, with a recurrence rate of 19.3%. Shanghai Changhai Hospital once used pongee silk strips to suspend and fix the rectum in over 20 cases of complete rectal prolapse in adults, with prolapse lengths ranging from 8 to 26 cm. The method involved suturing one end of two pongee silk strips (1 cm × 12 cm) to both sides of the anterior rectal wall and the other end to the sacral membrane and fascia below the sacral prominence. The posterior rectal wall was not dissected. In the first case, where the prolapse was 26 cm, after suspension and fixation, a temporary sigmoid colostomy was added without opening the intestine, and the intestine was returned to the abdominal cavity after one week, with good postoperative results. Over 20 cases were followed up for more than 10 years, with no recurrences.

(4) Anterior rectal wall plication: In 1953, Shen Kefei proposed the anterior rectal wall plication based on the pathogenesis of complete rectal prolapse in adults. The method involves mobilizing and elevating the rectum through the abdomen. The lower segment of the sigmoid colon is lifted upward, and multiple transverse plication sutures are made on the anterior wall of the upper rectum and lower sigmoid colon, either from top to bottom or bottom to top. Each layer is intermittently sutured with silk thread in 5–6 stitches. Each plication shortens the anterior rectal wall by 2–3 cm, with a 2 cm interval between each two layers. The plication should only pass through the seromuscular layer, not the intestinal lumen. By plicating the anterior rectal wall, the rectum is shortened and stiffened, and fixed to the sacrum (sometimes the lateral rectal wall is sutured to the presacral fascia). This addresses the pathology of the rectum itself and reinforces the fixation point at the rectosigmoid junction, aligning with the treatment principle for intussusception. Shanghai Changhai Hospital reported 41 cases, with only 4 recurrences (9.8%). Complications occurred in 12 cases, including lower abdominal pain during urination in 7 cases, residual urine in 2 cases, and one case each of abdominal abscess, wound infection, and medial abdominal neuritis.

(5) Nigro procedure: Nigro believed that due to the loss of contraction in the puborectalis muscle, the rectum could not be pulled forward, leading to an enlarged pelvic floor defect, disappearance of the "anorectal angle," and vertical positioning of the rectum, resulting in rectal prolapse. Therefore, he advocated reconstructing the rectal sling. Nigro used a Teflon strip to fix the lower rectum posteriorly and laterally, pulling it forward and suturing the Teflon strip to the pubis to reestablish the "anorectal angle." Postoperatively, the sling can be palpated on rectal examination, though it lacks contractile function. This procedure has advantages over sacral fixation, including better pelvic fixation and indirect support for the bladder, potentially improving bladder function. Nigro reported over 60 cases with more than 10 years of follow-up and no recurrences. The procedure is technically challenging, with major complications being bleeding and infection, requiring an experienced surgeon.

2. Resection of Prolapsed Bowel

(1) Altemeir procedure: Perineal resection of the rectosigmoid colon. Altemeir advocated perineal initial-stage [first-stage] resection of the prolapsed bowel. This procedure is particularly suitable for elderly patients unfit for abdominal surgery, those with prolonged prolapse that cannot be reduced, or cases with bowel necrosis.

The advantages are: ① Entering through the perineum allows clear visualization of anatomical variations, facilitating repair. ② The anesthesia does not need to be too deep, making it easier for elderly patients to tolerate. ③ Simultaneously repairs sliding hernias and removes redundant intestinal segments. ④ No need for artificial mesh transplantation, reducing the risk of infection. ⑤ Low mortality and recurrence rates. However, this method still has certain complications, such as perineal and pelvic abscesses, rectal stenosis, etc. Altemeir (1977) reported 159 cases, with 8 recurrences (5.03%). One death occurred. Early complications included 47 cases, such as perineal abscess (6 cases), bladder inflammation (14 cases), pyelonephritis (7 cases), atelectasis (7 cases), cardiac decompensation (6 cases), hepatitis (4 cases), ascites (3 cases). Advanced stage complications included 6 cases: pelvic abscess (4 cases), rectal stenosis (2 cases).

(2) Goldberg procedure, transabdominal resection of the sigmoid colon + fixation: Due to certain complications associated with perineal resection of the prolapsed bowel, Goldberg advocated freeing the rectum via the abdominal approach, elevating the rectum, and fixing the lateral wall of the rectum to the sacral membrane, while simultaneously resecting the redundant sigmoid colon, achieving good results. In 1980, he summarized 103 cases over 20 years (1952–1977), with only 1 death. During follow-up, 9 cases had mucosal prolapse, and recurrent cases were treated with phenol-vegetable oil injections or rubber band ligation, with excellent outcomes. Complications occurred in 12 cases (12%): 3 cases each of colonic obstruction and small intestine obstruction, and 1 case each of anastomotic leakage, wound dehiscence, severe presacral bleeding, fecal fistula, acute pancreatitis, and acute incarceration of esophageal hiatal hernia.

3. Anal encirclement (Thiersch procedure): A 1.5 cm wide fascial membrane or nylon/silicone rubber mesh band is placed around the anal canal to narrow the anus and prevent rectal prolapse. This method is only suitable for elderly and physically weak individuals. Technique: Small incisions are made anterior and posterior to the anus, and a curved hemostat is used to create a subcutaneous tunnel around the anal canal, connecting the two incisions. The nylon mesh band is then looped around the upper part of the anal canal and tied into a ring, allowing the anus to accommodate one finger. Postoperative complications include infection and fecal impaction, with a relatively high recurrence rate.

(3) Treatment Selection

There are many treatment methods for rectal prolapse, and the choice should be based on age, type of prolapse, and overall condition. Each surgical approach has its advantages, disadvantages, and recurrence rates, and no single method is suitable for all patients requiring surgery. Sometimes, multiple surgical methods may be needed for the same patient. For example, Goligher used 10 different surgical methods (153 procedures) for 152 cases of complete rectal prolapse; similarly, Shanghai Changhai Hospital employed 11 treatment methods for 78 cases of rectal prolapse before 1981. Regardless of the surgical method used, postoperative measures should aim to eliminate factors contributing to rectal prolapse and ensure firm adhesion between the surgically fixed rectum/sigmoid colon and surrounding tissues.

For children and elderly patients with incomplete or complete anorectal prolapse, non-surgical therapy should be attempted first. If ineffective, submucosal injection therapy within the rectum can be considered, with abdominal surgery rarely required. In adults, incomplete prolapse can be treated with injection therapy or longitudinal mucosal incision with transverse suturing. For complete prolapse in adults, intra-abdominal rectal fixation or suspension is safer, with lower complication, morbidity, and mortality rates, yielding good results. Partial resection of the sigmoid colon and rectum also shows favorable outcomes but carries a higher risk of postoperative complications. Irreducible prolapse or cases with bowel necrosis may require perineal resection of the rectum and sigmoid colon.