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Complications in Colorectal Surgery

David W. Dietz, MD

Vice-Chairman, Department of Colorectal Surgery

Digestive Disease Institute

Cleveland Clinic

Cleveland, OH


The ability to recognize and successfully manage complications is an essential step in the development of a competent surgeon.  Some of the more common and serious surgical complications encountered by colorectal surgeons are enterocutaneous fistulas, anastomotic leaks and strictures, injuries to the genitourinary structures, small bowel obstruction, pelvic bleeding, and wound infections.


Enterocutaneous Fistula


Enterocutaneous fistulas in the postoperative setting result from either unrecognized enterotomies or anastomotic leaks.  Attention to the technical details of surgery can minimize their occurrence.  Adequate repair of enterotomies and serosal tears, careful use of electrocautery, and thorough inspection of the bowel prior to abdominal closure are extremely important.  Enteric leaks can present in the first few days after surgery with diffuse peritonitis and septic shock or they may present later in the postoperative period as an abscess or enterocutaneous fistula.  In the first situation, the patient is best served by immediate return to the operating room for exploratory laparotomy.  Unrecognized enterotomies may be handled by either repair and proximal fecal diversion or exteriorization of the enterotomy as a loop stoma.  Primary repair without diversion is used rarely and only in highly selected cases. 


When the patient presents with an enterocutaneous fistula and is not in septic shock, a more conservative approach is generally advocated.  Initial management consists of placement of a nasogastric tube, bowel rest, broad spectrum antibiotic coverage, and pouching of the fistula site to quantify the volume of output and protect the skin from the caustic effects of the effluent.  A CT scan is usually obtained to rule out an associated abscess.  Total parenteral nutrition is started in anticipation of a period of fasting.  Over the next few days the surgeon will gain a sense of the volume of fistula output.  The fistula may be classified as high output (greater than 400 mL per day), moderate output (between 200 and 400 mL per day), or low output (less than 200 mL per day).  Spontaneous closure of an enterocutaneous fistula occurs in less than 50% of cases.  Chance of spontaneous closure is thought to be reduced by high volume of output, proximal location, distal obstruction, local sepsis, radiation exposure, a short or epithelialized fistula tract, malignancy, a foreign body in the fistula tract, Crohn's disease, and malnutrition.  Fistulas that close spontaneously usually do so within the first month.  If a fistula persists beyond this period of time, then plans should be made for surgical repair.  However, reoperation should be delayed until sepsis has resolved, nutritional stores have been repleated, and intra-abdominal adhesions have softened.  Most experienced reoperative surgeons prefer to wait at least 3-6 months.1,2  The ultimate healing rate after definitive surgical repair of an enterocutaneous fistula is approximately 80%.3  Areas of controversy are the role of enteral feeding in patients with enterocutaneous fistulas and the utility of somatostatin analogs in promoting  fistula closure.4



Anastomotic Complications


Anastomotic complications include bleeding, leaks, strictures, and fistulas.  These problems are usually related to technical factors (ischemia, tension, poor technique, stapler malfunction) or patient factors (local sepsis, poor nutrition, immunosuppression, morbid obesity, radiation exposure).  Sound technique in the construction of anastomoses can minimize risk, as can the preoperative correction of malnutrition and the use of proximal fecal diversion in patients with the above risk factors.


Anastomotic bleeding is common and varies in severity.  Most cases are mild and self-limited.  More serious bleeding, especially that from colonic or ileal pouches, can  be successfully managed with epinephrine (1:100,000) and saline retention enemas.  If this fails, or bleeding is massive and results in hemodynamic instability, the patient is best returned to the operating room for surgical intervention.  In cases of bleeding small bowel or proximal colonic anastomoses, angiography with selective infusion of vasopressin or embolization of the bleeding vessel may be indicated.


The incidence of anastomotic leak varies depending on the level of anastomosis.  Small bowel and ileocolic anastomoses have the lowest reported leak rates (1-3%).  The highest rates are after coloanal anastomoses (10-20%).  The risk of anastomotic leak after low anterior resection of the rectum is inversely related to the distance of the anastomosis from the anal verge.5  Neoadjuvant therapy may increase the risk of anastomotic leak following restorative proctectomy for cancer.  Leak rates of 5-10% had been reported after ileal pouch anal anastomosis and risk is increased in patients on greater than 40 mg per day of prednisone and possibly in those treated with biologic agents (infliximab).6,7  The creation of a diverting stoma proximal to a high risk anastomosis minimizes the severe consequences of a leak but does not reduce the incidence of leak itself .8-10  The role of pelvic drains in reducing the risk of anastomotic leak is controversial.11,12


The management of an anastomotic leak depends on whether the leak is “free” or “contained”.  "Free" leaks or those in which feculent fluid spreads throughout the abdominal cavity, leading to diffuse peritonitis and septic shock.  Patients with a free leak should undergo emergency laparotomy with control of the anastomotic leak (takedown and creation of an end stoma +/- mucous fistula, primary repair and proximal fecal diversion, wide drainage and proximal fecal diversion) along with abdominal washout.  “Contained” leaks are those in which extravasation of contrast material is limited to the perianastomotic space and often result in the development of an abscess.  These situations are usually managed by insertion of a radiologically-guided percutaneous drainage catheter.  Contained leaks managed in this manner may heal spontaneously or may result in the formation of a controlled enterocutaneous fistula often accompanied by an anastomotic stricture.  Reoperation to address an anastomotic fistula or stricture should be deferred for 6 months to allow for resolution of the intra-abdominal inflammatory state.


Genitourinary Complications


Ureter injuries in colorectal surgery most commonly occur during left-sided colon resections.  There are four particular areas of danger: During high ligation of the inferior mesenteric artery; during mobilization of the upper mesorectum at the level of the sacral promontory; during the deepest portion of the pelvic phase of proctectomy where the lower rectum, pelvic sidewall, and bladder base lie in proximity; and, during the deepest portion of the perineal phase of an abdominoperineal resection.  The key to avoiding a major complication is the intraoperative recognition and repair of a ureteral injury.  This may be facilitated by the use of ureteral stents.  Indigo carmine dye may also be administered if there is suspicion of ureteral injury. The retroperitoneal tissues are then inspected for staining.  Repair of ureteral injuries is best performed by a urologist if available.  Injuries to the upper third of the ureter or most commonly repaired by creation of an end to end spatulated anastomosis performed over a stent.  Injuries to the middle third of the ureter may be repaired primarily or by ligation of the distal stump and creation of a ureteroneocystostomy with a Boari flap or psoas hitch repair.  Injuries to the distal third of the ureter may be repaired by ligation of the distal stump and creation of a neo-ureterocystostomy.


Injuries to the urethra most commonly occur during abdominoperineal resection and involve the membranous or prostatic portions of the urethra.  Small injuries recognized at the time of surgery may be repaired primarily with a Foley catheter left in place for 2-4 weeks postoperatively.  Larger injuries or those that are not recognized until after surgery require proximal urinary diversion with a suprapubic catheter and delayed repair, often with the use of a gracilis muscle flap.


Bladder injuries are relatively common, especially in the setting of an adherent rectosigmoid tumor or diverticular phlegmon.  When the bladder wall is either resected or opened, the resulting defect can be closed in 2 layers with a Foley catheter left in place for 7-10 days postoperatively. A cystogram is often obtained prior to removal of the catheter to confirm healing.  Injuries to the base of the bladder are more difficult to handle.  The best approach is often by opening the dome of the bladder with repair of the injury to the trigone area performed from the inside.  This will allow direct visualization of the ureteral orifices and minimize the risk of inadvertent ligation.  Interposition of the omentum between any bladder repair and a bowel anastomosis is advised to prevent fistulization.


Sexual dysfunction occurs in 15-50% of male patients undergoing proctectomy for rectal cancer. The rate is influenced by factors such as patient age, preoperative libido, and neoadjuvant radiation therapy.13-15  Damage to the superior hypogastric (sympathetic) plexus most commonly results in retrograde ejaculation.  This is the most common type of sexual dysfunction seen in male patients after proctectomy and is also the type most likely to resolve with time.  Damage to the pelvic plexus on the pelvic sidewall or the nervi erigentes or cavernous nerves (parasympathetic) anteriorly may result in erectile dysfunction.  Preservation of the Denonvillier’s fascia, if possible, may reduce the risk of injury to these nerves.16  Sexual dysfunction also occurs in women after proctectomy, but data is lacking.17


Fertility may be reduced in women undergoing restorative proctocolectomy for ulcerative colitis or familial polyposis.  Recent studies have shown that the rate of infertility exceeds 50% in this group.18,19  Preoperative counseling is important and the timing of elective surgery should be carefully considered in women who are planning to have children.  Measures to reduce the formation of pelvic adhesions (suspending ovaries, use of anti-adhesion barriers) may be helpful, but have not been validated.


Trapped ovary syndrome is a related complication seen in young women following restorative proctocolectomy.  Pelvic adhesions trap the ovaries in the pelvis and cover the fallopian tubes. With each ovulatory cycle fluid may accumulate within these septated spaces and pelvic pain may result.  Diagnosis is made by CT scan or ultrasound.  Surgery for cyst unroofing and excision, pelvic adhesiolysis, and suspension of the ovaries is usually required.


Small Bowel Obstruction


Avoiding ischemia and perforation is the goal of management in patients with small bowel obstruction.  A large reported series of patients undergoing surgery for small bowel obstruction found strangulated bowel to be present in 16% of cases with the risk of death in this group increased by 4 fold.20  Signs and symptoms of strangulated bowel are fever, tachycardia, leukocytosis, sepsis, peritoneal signs, and the presence of continuous as opposed to intermittent abdominal pain.  These indicators, however, are not specific nor or they sensitive.  In one series, nearly a third of patients found to have strangulated bowel the time of surgery were not diagnosed preoperatively.21


CT scan of the abdomen and pelvis is probably the best test for both diagnosis and evaluation of the patient with small bowel obstruction.  The sensitivity of CT scan is 90-100%.  The sensitivity of plain radiographs in detecting a small bowel obstruction is approximately 60%.  Water-soluble contrast studies of the small bowel may predict non-resolution and the need for operative intervention and also may have some therapeutic efficacy.22-24


The initial management of the patient with small bowel obstruction is determined by the level of suspicion for strangulated bowel. If suspected, the patient should undergo emergency laparotomy after aggressive fluid resuscitation.  If signs of perforation or ischemia are absent, a trial of expectant management may be undertaken.  80% of such cases will resolve with a nonoperative approach consisting of nasogastric tube decompression, bowel rest, and fluid and electrolyte replacement.  Constant vigilance for the developing signs or symptoms of ischemia should be kept.  Failure of small bowel obstruction to resolve within 48 hours is a common indication for laparotomy.


Small bowel obstruction occurring within one month of abdominal surgery is a special situation.  Reoperation in these patients should only be undertaken in the event of uncontrollable sepsis or ischemic bowel.  Otherwise, extreme patience should be the rule.  Laparotomy during the postoperative period can be extremely difficult due to dense inflammatory adhesions and the risk of enterotomy, mesentery vascular injury, enterocutaneous fistula, and massive small bowel resection are significant.  These patients can be managed with total parenteral nutrition and a PEG tube for decompression.  Most early postoperative small bowel obstructions will resolve with conservative management, although it may take several months.


Pelvic Bleeding


Serious pelvic bleeding during surgery is usually due to injury to the presacral venous plexus or the internal iliac vessels or their branches.  Presacral venous bleeding can be difficult to control due to the fragile nature of the presacral venous plexus and its special anatomy.  Attempts at electrocoagulation or suture ligation may worsen the bleeding and should be avoided.  Direct pressure while the patient is resuscitated by the anesthesia team is usually the first step.  Once stabilized, methods such as sterile thumbtacks, occluded pins, or a rectus muscle patch is may be employed.25-27



Wound Infections


Wound infections occur in 5-15% of patients following colorectal surgical procedures.  Risk factors have been identified and include malnutrition, diabetes, immunosuppression, age greater than 60 years, American Society of Anesthesia score greater than 2, fecal contamination, length of hospitalization before surgery, and extensive surgery.28  Much attention has been given to the “SCIP measures” as a means to decrease the incidence of surgical site infections in colorectal surgery patients. SCIP measures are use of appropriate antibiotics, administration within 1 hour of incision, cessation within 24 hours of surgery, and maintenance of patient normothermia. The efficacy of these measures in reducing surgical site infections is debated.29,30 Recent studies, including a meta-analysis, suggest that mechanical bowel preparation does not decrease the incidence of wound infection.31-33 


Wound infections typically present around the fifth postoperative day and are treated by opening of the overlying skin incision.  The resulting wound is then packed and allowed to heal by secondary intention.  Vacuum-assisted wound closure devices may be beneficial, although the cost:benefit ratio is not clear.  Necrotizing wound infections are usually the result of either Clostridium perfringens or beta-hemolytic streptococcus and are potentially life-threatening. These infections generally present within the first several days after surgery and can be difficult to diagnose.  Unusually severe wound pain along with drainage of a thin gray fluid from the incision are highly suggestive.  These patients should be returned to the operating room for immediate wound exploration and debridement of all devitalized tissue.  Broad spectrum antibiotic coverage should include high-dose penicillin.


Intra-abdominal abscesses result from anastomotic leaks, enterotomies, pre-existing infection, or spillage of bowel contents at the time of surgery.  Most intra-abdominal or pelvic abscesses can be successfully treated with percutaneous catheter drainage performed under radiologic guidance.


Perineal wound infection and delayed healing complicate 11-50% of abdominoperineal resections.34-37  Risk factors have been identified including the use of neoadjuvant radiation therapy in patients with rectal cancer, prolonged operative time, intraoperative hypothermia, and fecal contamination.37-39  Patients undergoing proctectomy for complications of Crohn's disease are also at risk for a nonhealing perineal wound.  An intersphincteric dissection with closure of the external sphincter muscles in this situation may improve wound healing.  Perineal wound infections are managed similarly to those of abdominal incisions; namely, by opening of the incision to allow for drainage, debridement of devitalized tissue, and subsequent local wound care by either gauze packing or a vacuum-assisted wound closure device.  Complete healing may take many months and, in some cases, flap closure may be necessary.




1.      Berry SM, Fischer JE. Enterocutaneous fistulas. Curr Probl Surg 1994;31(6):469–566.

2.      Joyce MR and Dietz DW. Management of complicated gastrointestinal fistulas. Current Problems in Surgery 2008;46(5):373-432

3.      Lynch AC, Delaney CP, Senagore AJ, et al. Clinical outcome and factors predictive of recurrence after enterocutaneous fistula surgery. Ann Surg 2004;240(5):825-31.

4.      Sancho JJ, di Costanzo J, Nubiola P, et al. Randomized double-blind placebo-controlled trial of early octreotide in patients with postoperative enterocutaneous fistula. Br J Surg 1995;82(5):638–641.

5.      Vignali A, Fazio VW, Lavery IC, Milsom JW, Church JM, Hull TL, Strong SA, Oakley JR. Factors associated with the occurrence of leaks in stapled rectal anastomoses: a review of 1,014 patients. J Am Coll Surg 1997;185(2):105-13.

6.      Heuschen UA, Hinz U, Allemeyer EH, et al. Risk factors for ileoanal J pouch-related septic complications in ulcerative colitis and familial adenomatous polyposis. Ann Surg 2002;235(2):207-16

7.      Selvasekar CR, Cima RR, Larson DW, et al. Effect of infliximab on short-term complications in patients undergoing operation for chronic ulcerative colitis.  J Am Coll Surg 2007;204(5):956-62

8.      Marusch F, Koch A, Schmidt U, et al. Value of a protective stoma in low anterior resections for rectal cancer. Dis Colon Rectum 2002;45(9):1164–1171.

9.      Pakkastie TE, Ovaska JT, Pekkala ES, Luukkonen PE, Jarvinen HJ. A randomised study of colostomies in low colorectal anastomoses. Eur J Surg 1997;163(12):929–933.

10.  Dehni N, Schlegel RD, Cunningham C, Guiguet M, Tiret E, Parc R. Influence of a defunctioning stoma on leakage rates after low colorectal anastomosis and colonic J pouch-anal anastomosis. Br J Surg 1998;85(8):1114–1117.

11.  Merad F, Hay JM, Fingerhut A, et al. Is prophylactic pelvic drainage useful after elective rectal or anal anastomosis? A multicenter controlled randomized trial. French Association for Surgical Research. Surgery 1999;125(5):529–535.

12.  Urbach DR, Kennedy ED, Cohen MM. Colon and rectal anastomoses do not require routine drainage: a systematic review and meta-analysis. Ann Surg 1999;229(2):174–180.

13.  Walsh PC, Schlegel PN. Radical pelvic surgery with preservation of sexual function. Ann Surg 1988;208(4):391–400.

14.  Havenga K, Enker WE, McDermott K, Cohen AM, Minsky BD, Guillem J. Male and female sexual and urinary function after total mesorectal excision with autonomic nerve preservation for carcinoma of the rectum. J Am Coll Surg 1996;182(6):495–502.

15.  Masui H, Ike H, Yamaguchi S, Oki S, Shimada H. Male sexual function after autonomic nerve-preserving operation for rectal cancer. Dis Colon Rectum 1996;39(10):1140–1145.

16.  Lindsey I, Mortensen NJ. Iatrogenic impotence and rectal dissection. Br J Surg 2002;89(12):1493–1494.

17.  Havenga K, Enker WE, McDermott K, Cohen AM, Minsky BD, Guillem J. Male and female sexual and urinary function after total mesorectal excision with autonomic nerve preservation for carcinoma of the rectum. J Am Coll Surg 1996;182(6):495–502.

18.  Gorgun E, Remzi FH, Goldberg JM, et al. Fertility is reduced after restorative proctocolectomy with ileal pouch anal anastomosis: a study of 300 patients. Surgery 2004;136(4):795–803.

19.  Olsen KO, Joelsson M, Laurberg S, Oresland T. Fertility after ileal pouch-anal anastomosis in women with ulcerative colitis. Br J Surg 1999;86(4):493–495.

20.  Fevang BT, Fevang J, Stangeland L, Soreide O, Svanes K, Viste A. Complications and death after surgical treatment of small bowel obstruction: a 35-year institutional experience. Ann Surg 2000;231(4):529–537.

21.  Sarr MG, Bulkley GB, Zuidema GD. Preoperative recognition of intestinal strangulation obstruction. Prospective evaluation of diagnostic capability. Am J Surg 1983;145(1):176–182.

22.  Biondo S, Pares D, Mora L, Marti RJ, Kreisler E, Jaurrieta E. Randomized clinical study of gastrografin administration in patients with adhesive small bowel obstruction. Br J Surg 2003;90(5):542–546.

23.  Choi HK, Chu KW, Law WL. Therapeutic value of gastrografin in adhesive small bowel obstruction after unsuccessful conservative treatment: a prospective randomized trial. Ann Surg 2002;236(1):1–6.

24.  Chen SC, Lin FY, Lee PH, Yu SC, Wang SM, Chang KJ. Water-soluble contrast study predicts the need for early surgery in adhesive small bowel obstruction. Br J Surg 1998;85(12):1692–1694.

25.  Nivatvongs S, Fang DT. The use of thumbtacks to stop massive presacral hemorrhage. Dis Colon Rectum 1986;29(9):589–590.

26.  Stolfi VM, Milsom JW, Lavery IC, Oakley JR, Church JM, Fazio VW. Newly designed occluder pin for presacral hemorrhage. Dis Colon Rectum 1992;35(2):166–169.

27.  Remzi FH, Oncel M, Fazio VW. Muscle tamponade to control presacral venous bleeding: report of two cases. Dis Colon Rectum 2002;45(8):1109–1111.

28.  Platell C, Hall JC. The prevention of wound infection in patients undergoing colorectal surgery. J Hosp Infect 2001;49(4):233–238.

29.  Larochelle M, Hyman N, Gruppi L, Osler T. Diminishing surgical site infections after colorectal surgery with surgical care improvement project: is it time to move on? Dis Colon Rectum 2011;54(4):394-400.

30.  Wick EC, Vogel JD, Church JM, et al. Surgical site infections in a “high outlier” institution: are colorectal surgeons to blame? Dis Colon Rectum 2009;52(3):374-9.

31.  Slim K, Vicaut E, Panis Y, Chipponi J. Meta-analysis of randomized clinical trials of colorectal surgery with or without mechanical bowel preparation. Br J Surg 2004;91(9):1125–1130.

32.  Guenaga KF, Matos D, Castro AA, Atallah AN, Wille-Jorgensen P. Mechanical bowel preparation for elective colorectal surgery. Cochrane Database Syst Rev 2003;(2):CD001544.

33.  Slim K, Vicaut E, Panis Y, Chipponi J. Meta-analysis of randomized clinical trials of colorectal surgery with or without mechanical bowel preparation. Br J Surg 2004;91(9):1125–1130.

34.  Pollard CW, Nivatvongs S, Rojanasakul A, Ilstrup DM. Carcinoma of the rectum. Profiles of intraoperative and early post-operative complications. Dis Colon Rectum 1994;37(9):866–874.

35.  Rosen L, Veidenheimer MC, Coller JA, Corman ML. Mortality, morbidity, and patterns of recurrence after abdominoperineal resection for cancer of the rectum. Dis Colon Rectum 1982;25(3):202–208.

36.  Rothenberger DA, Wong WD. Abdominoperineal resection for adenocarcinoma of the low rectum. World J Surg 1992;16(3):478–485.

37.  Nissan A, Guillem JG, Paty PB, et al. Abdominoperineal resection for rectal cancer at a specialty center. Dis Colon Rectum 2001;44(1):27–35.

38.  Baudot P, Keighley MR, Alexander-Williams J. Perineal wound healing after proctectomy for carcinoma and inflammatory disease. Br J Surg 1980;67(4):275–276.

39.  Irvin TT, Goligher JC. A controlled clinical trial of three different methods of perineal wound management following excision of the rectum. Br J Surg 1975;62(4):287–291.