Rectal prolapse refers to the downward displacement of the anal canal, rectum and even the lower end of the sigmoid colon. Only the mucous membrane is prolapsed, and the whole rectum is prolapsed, which is called incomplete prolapse. If the prolapsed part is in the anorectum, it is called internal prolapse or internal prolapse, and if it is outside the anus, it is called external prolapse. Rectal prolapse is common in children, elderly people and menstruating mothers. The child type mostly disappears gradually and heals itself by the age of 5 years because the sacral curvature gradually forms and can effectively support the posterior rectal wall. In the adult type, prolapse will gradually increase as long as the cause of rectal prolapse exists. Prolonged prolapse will cause damage to the nerves in the pubic area and result in fecal incontinence.
According to the degree of prolapse, there are two types of prolapse: partial and complete.
① Partial prolapse (incomplete prolapse): the prolapsed part is only the mucosa of the lower rectum, so it is also called mucosal prolapse. The length of prolapse is 2-3cm, generally not more than 7cm, the mucosa is radial, the prolapse is composed of two layers of mucosa, and there is no groove gap between the prolapsed mucosa and the anus. Partial prolapse should be distinguished from circumferential internal hemorrhoid prolapse, the latter can be seen as congested hypertrophic hemorrhoid block, plum-shaped, easy to bleed, and there is a depressed normal mucosa between the hemorrhoid block, rectal finger diagnosis, the anal sphincter contraction is strong, while the rectal partial prolapse is relaxed, which is an important point of differentiation.
② complete prolapse: the whole layer of the rectum is prolapsed, in serious cases, the rectum and anal canal can be turned out to the outside of the anus, the length of prolapse is often more than 10cm, or even 20cm, in the shape of a pagoda, the mucosal folds are arranged in a ring, the prolapsed part is composed of two layers of folded intestinal wall, which is thicker to touch, and there is a peritoneal gap between the two layers of intestinal wall.
Whether pediatric or adult rectal prolapse, while using treatment, should try to eliminate the factors that produce prolapse, such as active treatment of chronic cough, diarrhea and constipation and other diseases that produce increased intra-abdominal pressure, and improve the nutritional status.
I. Injection therapy for rectal prolapse
Indications
(1) children with rectal mucosal prolapse, after symptomatic treatment failure, can use this method, the efficacy is good.
(2) Adult rectal mucosal prolapse, such as weakness, old age or other complications can not tolerate surgery, can be tried to temporarily reduce symptoms.
Contraindications
Injection therapy should not be used when mucosal prolapse is accompanied by acute infection, ulceration or necrosis.
Preoperative preparation
(1) Prepare a 10 ml syringe or a three-ring syringe. Use a 9-gauge penetrating needle or a special penetrating needle for the needle. This needle is adapted from the tonsil injection needle, and the tip of the needle is ground short, retaining about 0.5 cm long that is. The rear part of this needle is thicker, can avoid piercing too deep, especially suitable for beginners.
(2) hardener selected 5% carbolic acid vegetable oil solution (commonly used for refined peanut oil) is most appropriate. In case of cold days need to add temperature to make it liquefied.
(3) Empty the bowels and urine before injection.
Anesthesia and body position
Anesthesia is not required. Lateral, truncal and prone positions are acceptable.
Surgical procedure
The injection treatment for rectal prolapse includes submucosal injection and perirectal injection. The former injects drugs into the submucosa to make the mucosa adhere to the muscle layer; the latter injects drugs into the perirectum to make the rectum adhere to the surrounding area. The commonly used drugs are 5% petrolatum vegetable oil and alum injection. Alum (potassium aluminum sulfate) aqueous solution can make proteins and colloids denatured and coagulated, producing hemorrhagic coagulative necrosis, scar proliferation and forming stronger adhesions for therapeutic purposes. Aluminum ions in the alum solution are mainly retained locally in the injection, which is the main cause of foreign body colloid fibrosis. Aluminum preparation mainly acts locally, and a small amount can be absorbed by blood, but is quickly eliminated by kidney. The commonly used concentration is 5% to 8%.
(1) Submucosal injection method: After disinfection of the mucosa at the injection site by anoscopy. Inject 5% petrolatum vegetable oil 3~5m1 in each of the four quadrants of the anterior, posterior, left and right rectal submucosa 1cm above the dentate line.7~10d injections, generally 2~4 times. If 5% alum is used, 5ml is injected in each part, the total amount is 20ml, and the injection method is the same as above.
(2) perirectal injection method: that is, injection in both sides of the pelvic rectal gap (and posterior rectal gap. Take the lateral or prone position, disinfect around the anus routinely, and inject in both sides of the anus and in the posterior positive
Then inject 3~5ml at each mound to a depth of about 5~6cm, and then use a lumbar puncture needle to first stab the skin, subcutaneous, sciatic rectal space and anal tract muscle vertically in the right median to reach the pelvic rectal space. When passing through the anal raphe, the needle has a falling sensation. Before puncture, the injector will insert the finger into the rectum for guidance, touch the needle site, confirm that the needle is located in the lateral rectum, and then the puncture needle will gradually pierce to 5-7 cm, and after reaching the pelvic rectal space, the drug solution will be injected slowly in a fan shape, the total amount of 5% alum on one side is about 8-10 ml. When injecting the left side, another lumbar puncture needle will be replaced and injected in the same way. When injecting in the posterior median, proceed along the posterior wall of the rectum, pierce 4 cm, reach the posterior rectal space, and inject 4-5 ml of the drug.
The total amount of drugs injected in the three sites was 20-25 ml.
Points to note during the operation
(1) The first submucosal injection should be made to the highest point of the prolapsed mucosa, and then move down to above the dentate line one by one.
(2) Before injection around the rectum, the injector’s index finger should be inserted into the rectum for guidance to ensure that the needle does not pierce the rectum and prevent infection.
Postoperative treatment
(1) Bed rest is required for 2 to 3 days after injection.
(2) Take liquid paraffin wax 20m1 every night to keep the stool unobstructed.
(3) Fluid for 2 d, soft food with less residue for 3 d, and then change to general diet.
(4) Supplemental fluids and antibiotics for 3 to 4 d if necessary.
Major complications
(1) Complications of submucosal injection are the same as those of “hemorrhoid injection therapy”.
(2) Perirectal injection may occasionally cause low fever, lower abdominal distension, anal pain and difficulty in urination. If the puncture needle penetrates into the rectum, perirectal abscess and anal fistula may occur.
(3) In adults with incomplete prolapse or mild complete prolapse, if the sphincter is normal or slightly weak, treatment similar to 3 parent hemorrhoidectomy or rubber ring ligation is feasible, or sclerotherapy injection can be used. If the sphincter is relaxed, anal ring reduction or sphincteroplasty can be considered.
(4) Treatment of complete rectal prolapse in adults is mainly surgical, and the surgical routes are transabdominal, transperineal, transabdominal perineal and trans-sacral. There are many surgical methods, but each has its own advantages and disadvantages and recurrence rate. No single surgical method can be used for all patients, and sometimes several surgical methods are needed for the same patient. In the past, the surgery only paid attention to repairing the pelvic floor defect, and the recurrence rate was high. In recent years, the doctrine of rectal prolapse was studied, and the surgery paid attention to treating the rectum itself, and now the following surgeries are mostly used.
II. Rectal suspension and fixation
Indications
Complete rectal prolapse in adults.
Pre-operative preparation
(1) Same as general abdominal surgery, but intestinal preparation is required.
(2) Preoperative catheter is placed to facilitate intraoperative exposure.
(3) Prepare Teflon mesh suspension, Ivalon or silk band according to the requirements of each procedure.
Anesthesia and position
Continuous epidural anesthesia. Head down in supine position so that the small bowel is inverted towards the epigastrium to facilitate the exposure of the anterior rectal recess.
1. Ripstein procedure (Teflon suspension)
Surgical steps
(1) Through a left parasternal midline incision, about 20 cm long, the skin is incised and the subcutaneous layers are entered into the abdominal cavity. The small intestine is pushed all the way to the upper abdomen with a warm saline gauze pad.
(2) The posterior wall of the rectum is freed to the tip of the coccyx and the rectum is raised.
(3) The upper rectum is surrounded by a 5cra wide Teflon mesh suspensory band, fixed with fine nonabsorbable thread to the presacral fascia and periosteum under the sacral bulge, and the edge of the suspensory band is sutured to the anterior rectal wall and its lateral wall without repairing the pelvic floor.
(4) Finally, the peritoneal incision on both sides of the rectum and the layers of the abdominal wall were sutured.
Points to note during surgery
(1) The rectum should be completely freed to the pelvic floor, and the rectum should be elevated to keep it fixed.
(2) When suturing the rectal wall with Feflon, the rectum should not be damaged, and if the rectum is broken, it should not be implanted.
(3) Separate the posterior wall of the rectum to prevent anterior sacral bleeding.
(4) Hemostasis should be complete, otherwise it is easy to cause infection.
Postoperative treatment
(1) Enter liquid diet for 2 d after surgery.
(2) Give 20-30ml of liquid paraffin every night for the first 3 days after surgery until the stool is unobstructed.
(3) Postoperative bed rest for 2 weeks.
(4) Avoid heavy physical labor for 3 months after discharge from the hospital.
Major complications
The results of 1,111 Ripstein procedures have been reviewed, with a recurrence rate of 2.3% and complications of 16.5%, counting fecal blockage 6.7%, presacral bleeding 2.6%, stenosis l .8%, pelvic abscess 1.5%, small bowel obstruction 1.4%, impotence 1.8%, and fistula 0.4%.
2.1valon sponge implantation
Surgical steps
(1) The incision and free rectum are the same as “Ripstein surgery (1) and (2)”.
(2) Suture the semicircular Ivalon sponge sheet in the sacral recess with non-absorbable sutures, pull the rectum upward and place it in front of the Ivalon sheet; or just wrap it around the free rectum with sutures, without sutures with the sacrum to avoid bleeding in front of the sacrum.
(3) The Ivalon sponge is sutured to the lateral wall of the rectum, and the anterior rectal wall is kept open with a gap about 2-3 cm wide to avoid narrowing of the intestinal cavity.
(4) It has been advocated that when the Ivalon sponge is implanted, a quantity of antibiotic powder should be placed inside it to prevent infection.
(5) Covering the sponge piece and rectum with pelvic peritoneum.
(6) Finally, the entire abdominal wall is sutured.
Intraoperative points of attention
(1) The rectum should be freed to the bottom of the pelvis so that the rectum is elevated.
(2) Adequate colonic preparation should be done before surgery.
(3) The colon should not be implanted if it is inadvertently broken during surgery.
(4) Hemostasis should be complete, otherwise it is easy to cause infection.
(5) Ivalon should only be sutured to the lateral wall of the rectum, and the anterior wall of the rectum should be kept open for 2 to 3 cm to prevent rectal stenosis.
Postoperative treatment
Same as “Ripstein” surgery.
Major complications
Marti reviewed 688 cases by 10 authors. complications of Ivalon sponge implantation were as follows: ① infection accounted for 2.3%; ② recurrence rate: 3.3%.
3. Rectosacral suspension
In the early stage, two broad fasciae of the thigh were used to fix the rectum on the sacrum; in recent years, nylon and silk bands or two fasciae taken from the rectus abdominis sheath were advocated to replace the broad fasciae.
Surgical steps
(1) The incision is the same as the “Ripstein procedure”.
(2) The posterior rectal wall is usually not separated to avoid anterior sacral bleeding.
(3) Use two silk bands (for medical use), each about 2 cm wide and 10 cm long, and sew one end to the subacromial periosteum and fascia under the sacral bulge, and the other end to the plasma muscle layer of the lateral wall of the rectum. The other one was fixed at the sacrum and then sutured to the other side of the rectum through the colonic mesentery, and finally the peritoneum was sutured after the periosteum.
(4) The layers of the abdominal wall were sutured as usual.
Key points for attention during the operation
(1) Prevent bleeding when separating the periosteum under the sacral bulge.
(2) The silk band was sutured at the pulpy muscle layer of the lateral wall of the rectum. Prevent inadvertent puncture into the rectal cavity.
Postoperative management
Same as the “Ripstein procedure”.
Major complications
If the hemostasis is perfect and the sutures are closed as required, there are generally no special complications. Shanghai Changhai Hospital surgery has performed more than 20 cases, except for one case of abdominal wound full-layer dehiscence, no other complications.
4.Folding of anterior rectal wall
Surgical steps
(1) incision, the same as “Ripstein”.
(2) Reveal the rectal bladder (or rectal uterus) recess, and cut the peritoneum along the lowest part of the peritoneum of the anterior rectal wall to both sides of the upper rectum in an arc.
(3) Separate the retroperitoneal lax tissue straight to the tip of the coccyx, and then separate the anterior rectal lax tissue straight to the edge of the anal levator muscle. The anterior fascia of the originally incised rectal bladder sink was lifted upward and intermittently sutured to the raised anterior rectal wall with silk sutures.
(4) The lower sigmoid colon is lifted upward, and several layers of transverse folding sutures are made at the anterior wall of the upper rectum and lower sigmoid colon from top to bottom or white to bottom, with 5 or 6 interrupted sutures in each layer with fine nonabsorbable thread. Each folded layer can shorten the anterior rectal wall by 2 to 3 cm, and each two layers are folded 2 cm apart, and the length of the folded intestinal wall is generally 2 times as long as the prolapse (generally, it is appropriate to fold no more than 5 layers). As a result of folding the anterior rectal wall, the rectum is shortened, stiffened and fixed with the sacrum (sometimes the lateral wall of the rectum is sutured and fixed to the anterior sacral fascia), which not only solves the lesion of the rectum itself, but also reinforces the fixation point at the junction of the sigmoid and rectum, in line with the view of treating intussusception.
(5) Finally, the layers of the abdominal wall were sutured as usual.
Key points of intraoperative attention
(1) The depression of the folded intestinal wall must be downward to avoid inflammation caused by the accumulation of feces in it.
(2) When folding, the suture should only pass through the pulpy muscle layer and not through the intestinal cavity to prevent infection.
(3) Although the number of folding layers depends on the length of prolapse, the shortened length is preferably double the length of rectal prolapse, but if the length of rectal prolapse exceeds 10 cm, too much shortening may cause the risk of adhesions and intestinal obstruction, so it is not necessary to comply with the above shortened length requirements.
(4) The posterior rectal wall is not treated because the length of the prolapse of the anterior rectal wall is more than that of the posterior wall, and the posterior wall prolapse occurs after the anterior wall, so only folding the anterior rectal wall is sufficient to prevent the occurrence of rectal prolapse.
Postoperative treatment
Same as “Ripstein surgery”.
Main complications
(1) Lower abdominal pain during urination, mainly due to the intraoperative stretching of the bladder and the effect of raising the cysto-rectal recess on the bladder, which recovered within one month after surgery in all seven cases. Residual urine may be related to intraoperative separation of the posterior rectal wall damaging the nerve, and all recovered later.
(2) Abdominal abscess and wound infection.
(3) Early mucosal prolapse.
Third, partial colorectal resection
1. Trans-perineal prolapsed bowel resection
Most authors advocate transepithelial one-stage resection of prolapsed intestinal canal, with the following advantages.
① access from the perineum, so that the anatomical variation can be seen and repair can be facilitated.
(ii) Since no dissection is required, anesthesia need not be too deep, and the elderly can easily tolerate the procedure.
(iii) simultaneous repair of a sliding hernia and removal of a lengthy intestinal canal.
④No need to transplant artificial fabric, reducing the chance of infection.
⑤ Low mortality rate and recurrence rate.
Indications
(1) Rectal prolapse in the elderly.
(2) Those who have prolapsed for a long time and cannot be reset or have necrosis of the intestinal canal.
Surgical procedure
(1) Drag out the prolapsed intestinal canal by holding it with a tissue clamp and circumferentially cut the mucosa and muscle layer at 3 mm above the dentate line, pulling down the outer layer of the intestinal wall to reveal the inner layer; cut the sac formed by the descent of the peritoneum of the cysto-rectal fossa with the prolapsed rectum, and drag out the part of the sigmoid colon and rectum that is redundant due to prolapse through the mouth of the sac.
(2) After suturing the prolapsed peritoneal sac at a high level, the anal levator muscle is sutured anteriorly to the sigmoid and rectum.
(2) The prolapsed intestine was cut at the dentate line, the bleeding points were ligated sequentially, and an interrupted end-to-end anastomosis was made with chromium intestinal thread.
(4) After the surgery, one anal tube wrapped with petroleum jelly gauze was built into the anus.
Points to note during surgery
(1) The exenteric tube has two layers: inner and outer, with a peritoneal sac between them, and is connected to the free abdominal cavity. The small intestine is often prolapsed and embedded in it. Before resection, rectal palpation should be performed to clarify the aforementioned conditions. If there is small intestine embedded, it must be squeezed back.
(2) Aseptic technique must be observed during the operation.
Postoperative treatment
(1) Bed rest for 2 weeks after surgery, do not get up and walk.
(2) Give tincture of opium orally for 4~7d to keep constipation and prevent stool contamination.
(3) Remove the anal canal 6 to 7 d after surgery.
(4) Postoperatively, give hot magnesium sulfate liquid wet compress to improve mucosal edema.
(5) Continue antibiotic treatment after surgery. If there is infection, it must be controlled in time to avoid peritonitis.
Major complications
Post-operative complications mainly include the following two major categories.
(1) Early complications: perineal abscess, cystitis, pyelonephritis, pulmonary atelectasis, cardiac insufficiency, hepatitis, ascites.
(2) Late complications: pelvic abscess, rectal stenosis, recurrence of prolapse.
2.Anterior resection
The main advantage is that the lengthy sigmoid colon is removed without suspension and fixation, and the sigmoid colon can be removed after resection to eliminate the original possible bowel symptoms such as constipation, while other suspension procedures can sometimes aggravate the bowel symptoms. The disadvantage of resection is the risk of anastomotic leak, but the risk is minimal. The main point of the surgery is that the rectum should be free to the plane of the lateral ligament and the anastomosis should be performed at or below the plane of the sacral promontory to avoid recurrence. This procedure is similar to prerectal resection, so it has the complications of general colectomy anastomosis. In the past, Goldberg emphasized fixation of the rectum to the sacral periosteum, but Corman et al. believed that anterior resection was sufficient without additional fixation and the risk of hemorrhage caused when sewing the distal rectum to the anterior sacral fascia could be avoided.
IV. Anal circle reduction
In 1891, Thiersch introduced the use of silver wire placed in the subcutaneous tissue around the anus to tighten the relaxed sphincter to treat rectal prolapse, and later Turell simplified this procedure. The advantage of this method is that the operation is simple, the damage is small, and it can be performed under local anesthesia, but it is only a palliative operation and has certain complications, so not many people apply it. Recently, it has been proposed to use silicone rubber or nylon mesh band, which can be expanded and contracted because of its elasticity, which helps to prevent fecal incontinence and rectal prolapse.
Indications
(1) Rectal prolapse with weak anal contraction or anal relaxation.
(2) Elderly and debilitated rectal prolapse.
(3) Often used in conjunction with other methods of prolapse treatment.
Pre-operative preparation
Prepare a 30-gauge silver wire, polyester or silicone rubber mesh band according to the surgical requirements.
Anesthesia and position
Sacral canal anesthesia or local anesthesia. Prone or truncal position.
Surgical steps
(1) Make a 3-cm-long curved incision 1 to 2 cm from the anal verge in the anterior median position and incise the subcutaneous fascia.
(2) Using a curved vascular forceps, bluntly detach around the anal canal to the superficial and deep perineal muscles.
(3) When the left index finger is inserted into the rectum and the right index finger continues to be bluntly separated to the pelvic floor (at the inferior margin of the prostate in men and at the inferior margin of the cervix in women), the right index finger is separated posteriorly from the left and right sides of the anal canal and a tunnel is made on each side.
(4) Switching to the left glove, a 2-cm-long longitudinal incision is made between the caudal bone and the anal margin, and the external sphincter muscle gap is bluntly separated with curved vascular forceps to the caudal anal ligament.
(5) Enter the posterior rectal hiatus with the right index finger, separate the anal import side, and make a tunnel on each side to form a loop so that it can pass smoothly through the index finger.
(6) Enter the anterior incision with a large curved vascular forceps, pass through the right vessel tract, pass through the posterior incision, and clamp the end of the polyester mesh band to lead neatly out of the anterior incision.
(7) In the same way, the other end of the polyester mesh band is led from the posterior incision, through the left side tunnel, out of the anterior incision smoothly and meets the anterior incision.
(8) Insert a large anoscope (2-2.5 cm in diameter) into the anal canal as a basis for the size of the postoperative anal canal diameter, tighten the mesh band around the anoscope, overlap the two ends by 1 cm, make two interrupted sutures with silk thread to close the mesh band, and then remove the anoscope.
(9) The anterior and posterior incisions were pulled apart with pulling hooks, and the upper and lower poles of the mesh band and the muscular layer of the intestinal wall were fixed with non-absorbable thread for several stitches each to prevent the mesh band from shifting and folding.
(10) Finally, the perianal canal tissues and skin are closed layer by layer with intestinal thread and fine non-absorbable thread.
Points to note during the operation
(1) The circular tunnel should be able to pass smoothly through the index finger.
(2) Before suturing the mesh band, probe the tunnel with your finger to see if the mesh band is flat.
(3) The rectal mucosa should not be damaged during the operation to prevent infection. (Postoperative management]
(1) You can get out of bed early after surgery.
(2) Replenish fluids and apply antibiotics for 3 to 5 d.
(3) If there is blockage of fecal mass or poor defecation, use fingers to dilate the anus and give glycerin enema and take liquid paraffin every night.
Major complications
(1) Subcutaneous infection: If the infection is severe, the polyester mesh band should be removed.
(2) Fecal impaction: Mostly related to too tight anal ring constriction, which should generally be no less than the index finger. Most of the fecal impaction can be resolved with anal canal dilation and enema.
Treatment options
There are many treatments for rectal prolapse, and different treatments should be chosen according to age, type of prolapse and general condition. Each procedure has its advantages and disadvantages and recurrence rate, and no single procedure can be used for all patients who need surgery. For example, Goldberg used 10 surgical procedures (173 procedures) in 152 cases of complete rectal prolapse. A hospital in Shanghai also used 11 treatments for 8 cases of rectal prolapse before 1981. Regardless of the surgical procedure used, all factors causing rectal prolapse should be removed as much as possible after surgery so that the surgically fixed rectum and sigmoid colon are firmly adhered to the surrounding tissues.
Both incomplete and complete rectal prolapse in children and older adults should be treated first with non-surgical therapy, and if the results are poor, submucosal injection therapy in the rectum can be used, which rarely requires transabdominal surgery. In adults, incomplete prolapse can be treated with injection therapy and mucosal longitudinal and transverse suturing. In adults with complete prolapse, transabdominal rectal fixation or suspension is safer, with low complication, morbidity and mortality rates and good results. Partial sigmoidectomy and rectal resection are also more effective, but there are more postoperative complications. In cases of irreducible prolapse or intestinal necrosis, partial rectosigmoidectomy can be performed via the perineum.
Review
The true etiology of rectal prolapse is still not well understood, so there is no ideal surgery yet, and different procedures are usually chosen according to the patient’s age, type of prolapse and general condition.
Intrarectal sclerotherapy can achieve better results for incomplete rectal prolapse in children and older adults, but the recurrence rate is high. Injection therapy is not recommended for complete rectal prolapse in adults.
Rectal suspension and fixation: Ripstein and Ivalon procedures are commonly used in the US and UK, but some complications occur, such as fecal impaction, presacral bleeding, rectal stricture and pelvic infection, which are related to the implanted foreign body mesh band, so it is extremely important to avoid infection intraoperatively. Anterior rectal wall folding without the use of a foreign body is its advantage. For partial colorectal resection, anterior resection is currently advocated instead of transepithelial prolapsed bowel resection and transabdominal redundant sigmoid resection, because anterior resection is simple, does not require suspension and fixation, and does not require a foreign body mesh band, and has better surgical results.
Rectal prolapse is often associated with anal incontinence and constipation. Incontinence is the result of long-term straining and damage to the perineal and pubic nerves, and once fecal incontinence occurs, surgery often fails to improve bowel control. Therefore, it is important that surgery should be performed early before prolapse with incontinence. It should be noted that some patients who were not incontinent before surgery developed incontinence after surgery because the appearance of incontinence was masked by prolapsed bowel collaterals, and the symptoms of incontinence became apparent after correction of the prolapse. Therefore, for those with serious prolapse and long history, even if there is no history of incontinence before surgery, they should be alert and explain the possibility of postoperative incontinence to patients and their families to avoid unnecessary misunderstandings.
Constipation can exist before rectal prolapse, but its causes are unclear, and some people explain that.
① obstruction of the rectum by a prolapsed intestinal tube in the rectum.
(ii) a combination of slow colonic transmission.
(iii) uncoordinated contraction of the puborectalis muscle. Postoperative constipation may be related to scar formation and hardening of the rectum due to perirectal separation, which impairs the function of the rectum; separation of the lateral rectal ligament destroying the perirectal nerve; and obstruction due to excessive colonic length caused by suspension.