benign colorectal strictures can develop after diverticulitis , ischemic colitis , radiation colitis , or colonic resection . recently , colorectal endoscopic submucosal dissection has become another possible culprit for the development of this benign stricture , which usually occurs after resection of a lateral spreading tumor , occupying 75% of the lumen . anastomotic strictures after surgery , occurring in 5% to 20% of cases after low anterior resection , could be a serious condition that may require endoscopic or surgical treatment . despite this serious condition , most strictures could be managed successfully with several treatment modalities , such as direct digital dilation , transanal surgical treatment , endoscopic balloon dilation , and stent insertion . however , other varieties of endoscopic or surgical techniques are required in refractory strictures , especially after failure of the first endoscopic management . data on refractory cases in colorectal benign strictures are limited and this will be discussed . endoscopic balloon dilation has been used as a first treatment modality for the treatment of benign colorectal strictures . however , varying results have been reported with regard to the success rate of this procedure.1,2 despite its simplicity and immediate efficacy in up to 80% of cases , this technique requires several treatment sessions and is associated with a significant rate of recurrent benign stenosis . predictors of a successful outcome include : a relatively narrow stenosis ( < 10 mm ) , a short segment stricture ( < 4 cm ) , and anastomotic strictures . poor predictors include : numerous strictures , complete obstruction , associated fistulas within the stricture , active inflammation around the stricture , recent surgery , a tight angulation , and malignancy.3 balloons usually exert a radial vector force against the strictured tissue , and these often require sequential dilation using a larger balloon over two to three endoscopic sessions in order to achieve long - term success . however , this may not be determined until the results of the first dilation are known . immediate relief of symptoms has been reported in 77% of patients and long - term relief in 44% of patients.4 fifty - five patients with crohn symptomatic strictures were studied . the long - term success of endoscopic balloon dilation was reported to depend on the type of strictures , their location , and their length . failure of endoscopic treatment was observed in long - segment strictures in the terminal ileum.5 in one study , 55 patients with ileocolonic strictures secondary to crohn disease underwent 78 balloon dilations . dilatation resulted in complete relief of obstructive symptoms in 34 patients after one or repetitive dilatations . . however , four of these patients showed improvement with administration of intravenous fluid and antibiotics.6 balloon dilatation is more useful in patients with anastomotic strictures . in one study , endoscopic dilatation in 94 patients with postoperative anastomotic stenosis was successful in 59% of patients who underwent resection for cancer and in 88% who underwent resection for a benign condition . high success and low risk rates make endoscopic balloon dilatation the treatment of choice to avoid high risk of reoperation in patient with benign anstomoticstrictures.2 placement of a self - expandable metal stent ( sems ) has been suggested as one of therapeutic modalities for the relief of benign colorectal strictures.7 unlike uncovered stents , fully covered sems has several advantages in the management of benign strictures . these fully covered sems have limited local tissue reaction ; thus , they are used in benign conditions such as colonic strictures , fistulas , perforation , and leaks in the digestive tract.8,9 permanent insertion of sems is also associated with a significant and unacceptable rate of complications , such as new stricture formation and perforation . only a few studies have reported on the usefulness of fully covered sems in patients with benign colorectal strictures . one recent study , which included 43 patients with symptomatic strictures , reported on the effectiveness of fully covered sems in the management of benign colorectal strictures . the efficacy of the stent , technical success , stent retrieval , safety , and recurrence of symptoms were evaluated during the follow - up . the authors insisted that fully covered sems is safe and effective for treatment of symptomatic benign strictures , despite a high rate of spontaneous migration.10 although this study could not define the predictive risk factors for clinical success or recurrence , refractory patients who underwent several balloon dilation sessions were successfully managed . conduct of future studies will be needed in order to define the best treatment option , such as balloon dilation vs. early fully covered sems insertion . biodegradable stents have recently been developed for use in the management of refractory benign esophageal strictures . the poly - l - lactic based stent and polydiosanone based stent were mainly used for refractory benign esophageal strictures . in particular , a polydiosanone stent is a semicrystalline , biodegradable polymer , which degrades by random hydrolysis and at low ph . the prolonged dilatory effect before stent absorption and the progressive stent degradation could represent a favorable solution for patients with benign strictures refractory to standard dilation therapy compared with self - expandable metal and plastic stents for esophageal strictures.11,12 currently , use of biodegradable stents in the management of colorectal refractory benign strictures , same as benign esophageal strictures , has been attempted . treatment of 10 patients with postsurgical colorectal strictures ( n=7 ) and fistula ( n=3 ) with biodegradable polydiosanone stents was an effective alternative in short to medium terms . the fistulas were successfully closed in all patients . among the six patients who received stents for strictures , symptoms resolved in five ; in the remaining patients , the stent migrated shortly after the endoscopy . if biodegradable stents are to be used for the treatment of strictures and fistulas , the proximity of the stricture should be close to the anus because of the inflexibility , and the need to fix stents in the colon was important.13 in another study , 11 patients with postsurgical benign strictures located within 20 cm from the anal verge , refractory to mechanical or pneumatic dilation ( at least three sessions ) were included . the overall success rate of the biodegradable stent was 45%.14 treatment using biodegradable stents in the management of refractory anastomotic colorectal stricture is very safe . they concluded that , instead of a nondedicated biodegradable stent which carried a high migration risk , dedicated stents with a large diameter and antimigration findings could improve the outcome of patients with refractory benign colorectal stricture . endoscopic balloon dilation has been used as a first treatment modality for the treatment of benign colorectal strictures . however , varying results have been reported with regard to the success rate of this procedure.1,2 despite its simplicity and immediate efficacy in up to 80% of cases , this technique requires several treatment sessions and is associated with a significant rate of recurrent benign stenosis . predictors of a successful outcome include : a relatively narrow stenosis ( < 10 mm ) , a short segment stricture ( < 4 cm ) , and anastomotic strictures . poor predictors include : numerous strictures , complete obstruction , associated fistulas within the stricture , active inflammation around the stricture , recent surgery , a tight angulation , and malignancy.3 balloons usually exert a radial vector force against the strictured tissue , and these often require sequential dilation using a larger balloon over two to three endoscopic sessions in order to achieve long - term success . however , this may not be determined until the results of the first dilation are known . immediate relief of symptoms has been reported in 77% of patients and long - term relief in 44% of patients.4 fifty - five patients with crohn symptomatic strictures were studied . the long - term success of endoscopic balloon dilation was reported to depend on the type of strictures , their location , and their length . failure of endoscopic treatment was observed in long - segment strictures in the terminal ileum.5 in one study , 55 patients with ileocolonic strictures secondary to crohn disease underwent 78 balloon dilations . dilatation resulted in complete relief of obstructive symptoms in 34 patients after one or repetitive dilatations . . however , four of these patients showed improvement with administration of intravenous fluid and antibiotics.6 balloon dilatation is more useful in patients with anastomotic strictures . in one study , endoscopic dilatation in 94 patients with postoperative anastomotic stenosis was successful in 59% of patients who underwent resection for cancer and in 88% who underwent resection for a benign condition . high success and low risk rates make endoscopic balloon dilatation the treatment of choice to avoid high risk of reoperation in patient with benign anstomoticstrictures.2 placement of a self - expandable metal stent ( sems ) has been suggested as one of therapeutic modalities for the relief of benign colorectal strictures.7 unlike uncovered stents , fully covered sems has several advantages in the management of benign strictures . these fully covered sems have limited local tissue reaction ; thus , they are used in benign conditions such as colonic strictures , fistulas , perforation , and leaks in the digestive tract.8,9 permanent insertion of sems is also associated with a significant and unacceptable rate of complications , such as new stricture formation and perforation . only a few studies have reported on the usefulness of fully covered sems in patients with benign colorectal strictures . one recent study , which included 43 patients with symptomatic strictures , reported on the effectiveness of fully covered sems in the management of benign colorectal strictures . the efficacy of the stent , technical success , stent retrieval , safety , and recurrence of symptoms were evaluated during the follow - up . the authors insisted that fully covered sems is safe and effective for treatment of symptomatic benign strictures , despite a high rate of spontaneous migration.10 although this study could not define the predictive risk factors for clinical success or recurrence , refractory patients who underwent several balloon dilation sessions were successfully managed . conduct of future studies will be needed in order to define the best treatment option , such as balloon dilation vs. early fully covered sems insertion . biodegradable stents have recently been developed for use in the management of refractory benign esophageal strictures . the poly - l - lactic based stent and polydiosanone based stent were mainly used for refractory benign esophageal strictures . in particular , a polydiosanone stent is a semicrystalline , biodegradable polymer , which degrades by random hydrolysis and at low ph . the prolonged dilatory effect before stent absorption and the progressive stent degradation could represent a favorable solution for patients with benign strictures refractory to standard dilation therapy compared with self - expandable metal and plastic stents for esophageal strictures.11,12 currently , use of biodegradable stents in the management of colorectal refractory benign strictures , same as benign esophageal strictures , has been attempted . treatment of 10 patients with postsurgical colorectal strictures ( n=7 ) and fistula ( n=3 ) with biodegradable polydiosanone stents was an effective alternative in short to medium terms . the fistulas were successfully closed in all patients . among the six patients who received stents for strictures , symptoms resolved in five ; in the remaining patients , the stent migrated shortly after the endoscopy . if biodegradable stents are to be used for the treatment of strictures and fistulas , the proximity of the stricture should be close to the anus because of the inflexibility , and the need to fix stents in the colon was important.13 in another study , 11 patients with postsurgical benign strictures located within 20 cm from the anal verge , refractory to mechanical or pneumatic dilation ( at least three sessions ) were included . the overall success rate of the biodegradable stent was 45%.14 treatment using biodegradable stents in the management of refractory anastomotic colorectal stricture is very safe . they concluded that , instead of a nondedicated biodegradable stent which carried a high migration risk , dedicated stents with a large diameter and antimigration findings could improve the outcome of patients with refractory benign colorectal stricture . most benign colorectal strictures could be managed with several sessions of balloon dilation or fully covered sems insertion . several studies have reported on the use of combined endoscopic or a novel method other than these techniques . variable therapeutic options continue to evolve and have taken much of their lead from the treatment of refractory benign esophageal strictures . a combined technique of endoscopic electroincision using the tip of a polypectomy snare or papillotome and balloon dilatation was used in 36 patients with benign colorectal anastomotic strictures . recurrence of the stricture was found in only five of these patients at 1-year follow - up , and all were treated successfully by further balloon dilatation.15 the other combined modality was used at the completely obstructed anastomosis stricture . a puncture catheter ( polyethylene catheter ) with a needle and a flexible metallic sheath at the distal end could penetrate the central obstructed anastomosis stricture under endoscopic and fluoroscopic control . the guide - wire was passed through the catheter and pneumatic dilatation was then performed . more expandable dilatation was performed repeatedly for successful web destruction.16 another study also reported that endoscopic reanastomosis in a sigmoid cancer patient with a completely strictured colorectal anastomosis was performed successfully using a transrectal puncture needle and wire guided balloon dilatation.17 a novel hybrid technique using transanal endoscopic microsurgery ( tem ) and balloon dilation for the treatment of a benign complete colorectal anastomotic stricture has been reported.18 the stricture was incised with a vessel - sealing device using a 20-cm tem rectoscope . tem - assisted balloon strictureplasty could be a minimally invasive solution for bridging the gap between radical surgery and conservative treatment . in refractory benign strictures involved around the rectum , electrocautery can be performed via flexible sigmoidoscopy using a urologic resectoscope19 or by tem with balloon dilatation . laser ablation has also been reported for the treatment of strictures.20 one study reported the use of tem combined with a nd : yag laser for resection of an anastomotic stricture.21 dilation of the stricture using tem can be achieved at the same time as resection . novel endoscopic techniques are emerging for the management of refractory benign colorectal strictures ; these would be of great help in the management of patients who suffered from strictures . endoscopic dilation of colonic strictures offers many advantages over surgical management , including preservation of intestinal length . the procedure for balloon dilatation is quick , simple , and can be easily controlled by endoscopists . repeat dilations are often necessary , and the number of repeated dilations seems to vary between two and three or more . if a trial of several balloon dilatations fails , the patient will need an alternative modality . it is safe and effective for the treatment of refractory benign colonic strictures , despite a high rate of spontaneous migration . in particular , the biodegradable stent is very safe and does not need to be retrieved because it will be degraded naturally with tissue reaction . combined investigational modality can also be considered if only one modality like balloon or sems can not be performed due to a poor situation ( e.g. , numerous strictures ) . wire guided balloon dilation after use of a puncture needle , eletroincision , and tem using balloon dilatation and combined techniques could be attempted . these different treatments suggest that a single method is not adequate for all refractory benign colorectal strictures . what is important is that the etiology and pathogenesis behind colorectal stricture should be analyzed , given the success rate of a nonoperative intervention method . finally , surgical treatment is reserved for patients who fail all endoscopic remediation or those are not candidates for endoscopic treatment ( fig .
in colonoscopic study , benign colorectal strictures with or without symptomatic pain are not rarely encountered . 
 benign colorectal stricture can be caused by a number of problems , such as anastomotic stricture after surgery , inflammatory bowel disease , postendoscopic submucosal dissection , diverticular disease , ischemic colitis , and so on . 
 there are various modalities for the management of benign colorectal stricture . 
 endoscopic balloon dilatation is generally considered as the primary treatment for benign colorectal stricture . in refractory benign colorectal strictures , 
 several treatment sessions of balloon dilatation are needed for successful dilatation . 
 the self - expandable metal stent and many combined techniques are performed at present . 
 however , there is no specific algorithmic modality for refractory benign colorectal strictures .