The role of endoscopy in patients with anorectal disorders

Abstract

This is one of series of statements discussing the use of GI endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy (ASGE) prepared this text. In preparing this guideline, a search of the medical literature was performed by using PubMed. Studies or reports that described fewer than 10 patients were excluded from analysis if multiple series with more than 10 patients addressing the same issue were available. Additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. Guidelines for appropriate use of endoscopy are based on a critical review of the available data and expert consensus at the time the guidelines are drafted. Further controlled clinical studies may be needed to clarify aspects of this guideline. This guideline may be revised as necessary to account for changes in technology, new data, or other aspects of clinical practice. The recommendations are based on reviewed studies and were graded on the strength of the supporting evidence (Table 1).1Guyatt G.H. Oxman A.D. Vist G.E. et al.GRADE Working GroupGRADE: an emerging consensus on rating quality of evidence and strength of recommendations.BMJ. 2008; 26: 924-926Crossref Google Scholar The strength of individual recommendations is based on both the aggregate evidence quality and an assessment of the anticipated benefits and harms. Weaker recommendations are indicated by phrases such as “we suggest,” whereas stronger recommendations are typically stated as “we recommend.”TABLE 1GRADE system for rating the quality of evidence for guidelinesAdapted from Guyatt et al.1Guyatt G.H. Oxman A.D. Vist G.E. et al.GRADE Working GroupGRADE: an emerging consensus on rating quality of evidence and strength of recommendations.BMJ. 2008; 26: 924-926Crossref Google ScholarQuality of evidenceDefinitionSymbolHigh qualityFurther research is very unlikely to change our confidence in the estimate of effect.⊕⊕⊕⊕Moderate qualityFurther research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.⊕⊕⊕○Low qualityFurther research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.⊕⊕○○Very low qualityAny estimate of effect is very uncertain.⊕○○○ Open table in a new tab This guideline is intended to be an educational device to provide information that may assist endoscopists in providing care to patients. This guideline is not a rule and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment. Clinical decisions in any particular case involve a complex analysis of the patient's condition and available courses of action. Therefore, clinical considerations may lead an endoscopist to take a course of action that varies from these guidelines.Symptoms related to anorectal disorders are common among patients presenting to gastroenterologists and are sometimes challenging to manage. Some require the combined effort of both gastroenterologists and surgeons. Although it is beyond the scope of this article to discuss all abnormalities, common problems are reviewed. This document is a revision of a previous American Society for Gastrointestinal Endoscopy (ASGE)2Eisen G.M. Dominitz J.A. Faigel D.O. et al.American Society for Gastrointestinal EndoscopyStandards of Practice Committee Endoscopic therapy of anorectal disorders.Gastrointest Endosc. 2001; 53: 867-870Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar guideline and discusses the role of endoscopy in patients with anorectal disorders, including chronic radiation proctopathy, anal fissures, internal hemorrhoids and fecal incontinence. Additional information about the role of endoscopy in the evaluation of patients with perianal disease in inflammatory bowel disease is described in another ASGE guideline.3Leighton J.A. Shen B. Baron T.H. et al.Standards of Practice Committee, American Society for Gastrointestinal EndoscopyASGE guideline: endoscopy in the diagnosis and treatment of inflammatory bowel disease.Gastrointest Endosc. 2006; 63: 558-565Abstract Full Text Full Text PDF PubMed Scopus (188) Google ScholarChronic radiation proctopathyAmong patients receiving prostate irradiation, the rectum is the most common segment of the GI tract that is affected, with chronic radiation-induced injury occurring in up to 20% of patients.4Kinsella T.J. Bloomer W.D. Tolerance of the intestine to radiation therapy.Surg Gynecol Obstet. 1980; 151: 273-284PubMed Google Scholar, 5Buchi K. Radiation proctitis: therapy and prognosis.JAMA. 1991; 265: 1180-1186Crossref PubMed Scopus (44) Google Scholar The term radiation proctitis is a misnomer because there is no inflammatory component found on the biopsy sample, but there is the presence of ischemic endarteritis of the submucosal arterioles and submucosal fibrosis. Chronic radiation proctopathy can occur from 9 months to 30 years after pelvic radiation injury, although patients typically present within 2 years after radiation.6Karamanolis G. Triantafyllou K. Tsiamoulos Z. et al.Argon plasma coagulation has a long-lasting therapeutic effect in patients with chronic radiation proctitis.Endoscopy. 2009; 41: 529-531Crossref PubMed Scopus (65) Google Scholar Symptoms may include hematochezia, tenesmus, diarrhea, and defecatory urgency, whereas the endoscopic appearance ranges from diffuse, friable angioectatic lesions to frank ulceration. Approximately 95% of mild radiation-induced proctopathy is temporary and self-limited, and up to 5% of patients experience symptoms that are refractory to conservative management. Treatment of radiation proctopathy that is found incidentally on endoscopy is not usually indicated unless there are signs (eg, anemia) or symptoms that affect the patient's overall health status or quality of life because mild proctopathy will spontaneously resolve in the majority of patients. Complications of radiation proctopathy include anemia, rectal strictures, rectovesical fistula formation,7Jao S.W. Beart R.W. Gunderson L.L. Surgical treatment of radiation injuries to the colon and rectum.Am J Surg. 1986; 151: 272-277Abstract Full Text PDF PubMed Scopus (76) Google Scholar and increased risk of colorectal cancer.8Nieder A.M. Porter M.P. Soloway M.S. Radiation therapy for prostate cancer increases subsequent risk of bladder and rectal cancer: a population based cohort study.J Urol. 2008; 180 (discussion 2009-10): 2005-2009Abstract Full Text Full Text PDF PubMed Scopus (135) Google Scholar, 9Kendal W.S. Nicholas G. A population-based analysis of second primary cancers after irradiation for rectal cancer.Am J Clin Oncol. 2007; 30: 333-339Crossref PubMed Scopus (52) Google Scholar, 10Baxter N.N. Tepper J.E. Durham S.B. et al.Increased risk of rectal cancer after prostate radiation: a population-based study.Gastroenterology. 2005; 128: 819-824Abstract Full Text Full Text PDF PubMed Scopus (161) Google ScholarTreatmentA variety of treatments have been described for the management of chronic radiation proctopathy, including oral therapy (eg, 5-aminosalicylates, metronidazole, antioxidants), topical formalin application, rectal instillation therapy (eg, hydrocortisone, sucralfate, 5-aminosalicylates, short-chain fatty acids, metronidazole), thermal therapy (eg, argon plasma coagulation, heater probe,11Jensen D.M. Machiado G.A. Chang S. et al.A randomized, prospective study of endoscopic bipolar electrocoagulation and heater probe treatment of chronic rectal bleeding from radiation telangiectasias.Gastrointest Endosc. 1997; 45: 20-25Abstract Full Text Full Text PDF PubMed Scopus (115) Google Scholar laser), and hyperbaric oxygen.12Leiper K. Morris A.I. Treatment of radiation proctitis.Clin Oncol. 2007; 19: 724-729Abstract Full Text Full Text PDF Scopus (80) Google Scholar There are no large randomized, controlled studies of the management of chronic radiation proctopathy, and most of the data are based on case series and small trials.13Denton A. Forbes A. Andreyev J. et al.Non surgical interventions for late radiation proctitis in patients who have received radical radiotherapy to the pelvis.Cochrane Database Syst Rev. 2002; (CD003455)Google ScholarMedical therapySeveral medical therapies are briefly described here. In one prospective case series of 14 patients, rectal sucralfate suspension relieved symptoms in 11 patients over a mean follow-up of 6 months.14Gul Y.A. Prasannan S. Jabar F.M. et al.Pharmacotherapy for chronic hemorrhagic radiation proctitis.World J Surg. 2002; 26: 1499-1502Crossref PubMed Scopus (43) Google Scholar Sucralfate enemas (2 g twice daily) have been found to be superior to the combination of oral sulfasalazine and steroid enemas in controlling symptoms (94% vs 53%, P < .05) in a prospective, randomized trial of 37 patients.15Kochhar R. Patel F. Dhar A. et al.Radiation-induced proctosigmoiditis A prospective, randomized, double-blind controlled trial of oral sulfasalazine plus rectal steroids versus rectal sucralfate.Dig Dis Sci. 1991; 36: 103-107Crossref PubMed Scopus (204) Google Scholar In a case series of 26 patients with moderate to severe radiation proctopathy, sucralfate suspension twice daily was associated with a good symptom response in 77% by 4 weeks and 92% by 16 weeks.16Kochhar R. Sriram P.V. Sharma S.C. et al.Natural history of late radiation proctosigmoiditis treated with topical sucralfate suspension.Dig Dis Sci. 1999; 44: 973-978Crossref PubMed Scopus (118) Google Scholar 5-Aminosalicylic acid enemas failed to improve symptoms or the endoscopic appearance of the rectal mucosa in a prospective, open-label trial.17Baum C.A. Biddle W.L. Miner P.B. Failure of 5-aminosalicylic acid enemas to improve chronic radiation proctitis.Dig Dis Sci. 1989; 34: 758-760Crossref PubMed Scopus (108) Google Scholar Similarly, treatment with butyric acid enemas failed to result in significant improvements in symptom, endoscopic, and histologic scores in a randomized, double-blind, placebo-controlled, crossover trial in 12 patients.18Talley N.A. Chen F. King D. et al.Short-chain fatty acids in the treatment of radiation proctitis A randomized, double-blind, placebo-controlled, cross-over pilot study.Dis Colon Rectum. 1997; 40: 1046-1050Crossref PubMed Scopus (107) Google Scholar In a randomized, double-blind, crossover trial of 120 patients, hyperbaric oxygen treatment was associated with an absolute risk reduction for nonhealing of 32% (number needed to treat = 3) and enhanced bowel-specific quality of life.19Clarke R.E. Tenorio L.M. Hussey J.R. et al.Hyperbaric oxygen treatment of chronic refractory radiation proctitis: a randomized and controlled double-blind crossover trial with long-term follow-up.Int J Radiat Oncol Biol Phys. 2008; 72: 1621Abstract Full Text Full Text PDF Google Scholar In a Cochrane review, significant improvement was seen in healing of radiation proctopathy with hyperbaric oxygen treatment (P = .02).20Bennett M.H. Feldmeier J. Hampson N. et al.Hyperbaric oxygen therapy for late radiation tissue injury.Cochrane Database Syst Rev. 2005; (CD005005)Google Scholar In a open-label pilot study of 20 patients using a combination of vitamin E (400 IU 3 times daily) and vitamin C (500 IU 3 times daily), there was a significant symptomatic improvement in bleeding, diarrhea, and urgency.21Kennedy M. Bruninga K. Mutlu E.A. et al.Successful and sustained treatment of chronic radiation proctitis with antioxidant vitamins E and C.Am J Gastroenterol. 2001; 96: 1080-1084Crossref PubMed Google ScholarEndoscopic therapyEndoscopic therapy for radiation proctopathy includes thermal coagulation therapy and topical formalin application. The neodymium yttrium aluminum garnet laser has been effectively used in the treatment of radiation proctopathy and delivers a deeper tissue effect than the argon and potassium titanyl phosphate lasers. A median of 3 treatment sessions (range 1-9) is usually needed to obtain an optimal clinical response.22Viggiano T.R. Zighelboim J. Ahlquist D.A. et al.Endoscopic Nd:YAG laser coagulation of bleeding radiation proctopathy.Gastrointest Endosc. 1993; 39: 513-517Abstract Full Text PDF PubMed Scopus (71) Google Scholar, 23Carbatzas C. Spencer G.M. Thorpe S.M. et al.Nd:YAG Laser treatment for bleeding radiation proctitis.Endoscopy. 1996; 28: 497-500Crossref PubMed Scopus (76) Google Scholar, 24Alexander T.J. Dwyer R.M. Endoscopic Nd:YAG laser treatment of severe radiation injury of the lower gastrointestinal tract: long-term follow-up.Gastrointest Endosc. 1988; 34: 407-411Abstract Full Text PDF PubMed Scopus (54) Google Scholar, 25Ventrucci M. Di Simone M.P. Giulietti P. et al.Efficacy and safety of Nd:YAG laser for the treatment of bleeding from radiation proctocolitis.Dig Liver Dis. 2001; 33: 230-233Abstract Full Text PDF PubMed Google Scholar, 26Taylor J.G. DiSario J.A. Bjorkman D.J. KTP laser therapy for bleeding from chronic radiation proctopathy.Gastrointest Endosc. 2000; 52: 353-357Abstract Full Text Full Text PDF PubMed Scopus (62) Google Scholar However, laser treatments are expensive and the equipment is not widely available.Argon plasma coagulation (APC) has become the predominant endoscopic therapy for chronic radiation proctopathy because of its advantages over laser treatment, including lower cost, portability, and the ability to apply noncontact thermal therapy in tangential locations. APC is associated with reduced rectal bleeding in 80% to 90% of cases of radiation proctopathy and may improve the other troublesome symptoms of diarrhea and urgency.27Postgate A. Saunders B. Tjandra J. et al.Argon plasma coagulation in chronic radiation proctitis.Endoscopy. 2007; 39: 361-365Crossref PubMed Scopus (80) Google Scholar Typically, 1 to 3 treatment sessions are required to achieve bleeding control with power settings of 25 to 60 W and flow rates of 0.5 to 2.5 L/min.28Wilson S.A. Rex D.K. Endoscopic treatment of chronic radiation proctopathy.Curr Opin Gastroenterol. 2006; 22: 536-540Crossref PubMed Scopus (36) Google Scholar In a prospective study of 56 patients, all patients with mild proctopathy (n = 27) and 79% of those with severe disease (n = 29) had cessation of rectal bleeding and/or no recurrence of anemia (P < .05).6Karamanolis G. Triantafyllou K. Tsiamoulos Z. et al.Argon plasma coagulation has a long-lasting therapeutic effect in patients with chronic radiation proctitis.Endoscopy. 2009; 41: 529-531Crossref PubMed Scopus (65) Google Scholar During a mean follow-up of 17.9 months (range 6-33 months), 34 of 38 patients (90%) remained in clinical remission. Recurrence of rectal bleeding was higher in those using anticoagulants or aspirin (P = .02). Reported complications include rectal stenosis29Canard J.M. Védrenne B. Bors G. et al.Long term results of treatment of hemorrhagic radiation proctitis by argon plasma coagulation.Gastroenterol Clin Biol. 2003; 27: 455-459PubMed Google Scholar and fistulae30Chino A. Uragami N. Hosaka H. et al.Therapeutic strategy for hemorrhagic radiation proctitis—the optimum condition of argon plasma coagulation (APC).Nippon Shokakibyo Gakkai Zasshi. 2005; 102: 1405-1411PubMed Google Scholar in a minority of patients. Colonic explosions have been reported in patients who receive only an enema bowel preparation before APC.31Ben-Soussan E. Antonietti M. Savoye G. et al.Argon plasma coagulation in the treatment of hemorrhagic radiation proctitis is efficient but requires a perfect colonic cleansing to be safe.Eur J Gastroenterol Hepatol. 2004; 16: 1315-1318Crossref PubMed Scopus (59) Google Scholar In patients with cardiac pacemakers and defibrillators, caution and recommendations are the same as for the other endoscopic electrocautery systems.32Faigel D.O. Eisen G.M. Baron T.H. et al.Standards of Practice CommitteeAmerican Society for Gastrointestinal EndoscopyPreparation of patients for GI endoscopy.Gastrointest Endosc. 2003; 57: 446-450Abstract Full Text Full Text PDF PubMed Scopus (18) Google ScholarDilute (eg, 2%-10%) formalin topical treatment of radiation proctopathy has been applied either through a rigid proctoscope or instilled into the rectum. Complete clinical responses range from 63% to 100%.33Vyas F.L. Mathai V. Selvamani B. et al.Endoluminal formalin application for haemorrhagic radiation proctitis.Colorectal Dis. 2006; 8: 342-346Crossref PubMed Scopus (17) Google Scholar, 34Stern D.R. Steinhagen R.M. Anorectal cancer following topical formalin application for haemorrhagic radiation proctitis.Colorectal Dis. 2007; 9: 275-278Crossref PubMed Scopus (13) Google Scholar, 35Mathai V. Seow-Choen F. Endoluminal formalin therapy for haemorrhagic radiation proctitis.Br J Surg. 1995; 82: 190Crossref PubMed Scopus (68) Google Scholar, 36Biswal B.M. Lal P. Rath G.K. et al.Intrarectal formalin application, an effective treatment for grade III haemorrhagic radiation proctitis.Radiother Oncol. 1995; 35: 212-215Abstract Full Text PDF PubMed Scopus (64) Google Scholar In a retrospective analysis of 100 patients with a mean follow-up of 18 months, 10% formalin was applied by using a 16-inch cotton tip applicator passed through a proctoscope in the office setting.37Haas E.M. Bailey H.R. Farragher I. Application of 10 percent formalin for the treatment of radiation-induced hemorrhagic proctitis.Dis Colon Rectum. 2007; 50: 213-217Crossref PubMed Scopus (62) Google Scholar Cessation of bleeding occurred in 93% of patients after an average of 3.5 formalin applications at 2- to 4-week intervals. Approximately 1% of these patients experienced anal pain and spasm or transient dizziness. Complications, including anal stenosis, mucosal ulceration, and mild fecal incontinence have been reported.38Saclarides T.J. King D.G. Franklin J.L. et al.Formalin instillation for refractory radiation-induced hemorrhagic proctitis Report of 16 patients.Dis Colon Rectum. 1996; 39: 196-199Crossref PubMed Scopus (99) Google Scholar, 39Yegappan M. Ho Y.H. Nyam D. et al.The surgical management of colorectal complications from irradiation for carcinoma of the cervix.Ann Acad Med Singapore. 1998; 27: 627-630PubMed Google Scholar, 40Parikh S. Hughes C. Salvati E.P. et al.Treatment of hemorrhagic radiation proctitis with 4 percent formalin.Dis Colon Rectum. 2003; 46: 596-600Crossref PubMed Scopus (63) Google Scholar Radiofrequency ablation using an endoscopically directed focal ablation device and endoscopic cryotherapy have also been described in small case series.41Zhou C. Adler D.C. Becker L. et al.Effective treatment of chronic radiation proctitis using radiofrequency ablation.Ther Adv Gastroenterol. 2009; 2: 149-156Crossref PubMed Scopus (66) Google Scholar, 42Kantsevoy S.V. Cruz-Correa M.R. Vaughn C.A. et al.Endoscopic cryotherapy for the treatment of bleeding mucosal vascular lesions of the GI tract: a pilot study.Gastrointest Endosc. 2003; 57: 403-406Abstract Full Text Full Text PDF PubMed Scopus (84) Google Scholar Overall, considering the superficial nature of injury and wide availability of APC and topical formalin, these methods are practical first-line approaches to the endoscopic management of chronic radiation proctopathy. Relative contraindications for endoscopic therapy include evidence of malignant recurrence, stenosis, and fistulae. All thermal treatment methods may create symptomatic ulceration (including pain and bleeding), which can require months to resolve.Anal fissureAn anal fissure is a tear in the anal mucosa below the dentate line, characterized by pain and bleeding with defecation. Anal fissures are also associated with Crohn's disease, although the most common causes are local trauma from hard stool, hypertension of the internal anal sphincter, multiparity, or previous surgery.43Keck J.O. Staniunas R.J. Coller J.A. et al.Computer-generated profiles of the anal canal in patients with anal fissure.Dis Colon Rectum. 1995; 38: 72-79Crossref PubMed Scopus (66) Google Scholar Fissures usually arise in the posterior midline, but may also be seen in the anterior midline in 19%,44Hananel N. Gordon P.H. Re-examination of clinical manifestations and response to therapy of fissure-in-ano.Dis Colon Rectum. 1997; 40: 229-233Crossref PubMed Scopus (89) Google Scholar and ischemia is involved in the pathogenesis.45Schouten W.R. Briel J.W. Auwerda J.J. Relationship between anal pressure and anodermal blood flow The vascular pathogenesis of anal fissures.Dis Colon Rectum. 1994; 37: 664Crossref PubMed Scopus (284) Google Scholar, 46Klosterhalfen N. Vogel P. Rixen H. et al.Topography of the inferior rectal artery: a possible cause of chronic primary anal fissure.Dis Colon Rectum. 1989; 32: 43-52Crossref PubMed Scopus (205) Google Scholar Diagnosis is suggested by the history with characteristic symptoms of a “tearing” pain associated with bowel movements. Endoscopy should be considered when the diagnosis is in doubt, if bleeding occurs, to rule out associated inflammatory bowel disease and for patients due for a screening colonoscopy. However, temporarily deferring colonoscopy until after initial treatment of the anal fissure may help to avoid the discomfort associated with bowel preparation and colonoscopy in these patients. Anal fissures are best visualized with the patient lying on his or her side in the knee-to-chest position and by distracting the buttocks. Although acute fissures appear as a laceration, chronic fissures appear as linear white-based lesions with horizontally oriented fibers, typically associated with an external skin tag (sentinel tag) and hypertrophied anal papillae.Nonsurgical TreatmentIf constipation is present, acute fissures should be managed conservatively with stool softeners, fiber, fluids, and lubricants such as mineral oil and flaxseed oil. For chronic anal fissures, initial medical therapy is typically recommended except for fissures associated with an abscess or fistula. However, a Cochrane review concluded that medical therapy in adults is far less effective than surgery.47Nelson R. Non surgical therapy for anal fissure.Cochrane Database Syst Rev. 2006; (CD003431)Google Scholar Medical therapies that have been used include fiber supplementation, topical therapy (ie, mineral oil, anesthetics, nitroglycerin, calcium channel blockers), corticosteroids, calcium channel blockers, and botulinum toxin injection.48Billingham R.P. Isler J.T. Kimmins M.H. et al.The diagnosis and management of common anorectal disorders.Curr Probl Surg. 2004; 41: 586-645Abstract Full Text Full Text PDF PubMed Scopus (43) Google Scholar Although a meta-analysis of topical nitroglycerin demonstrated significant benefit in healing compared with placebo (odds ratio for fissure persistence = 0.55), side effects (especially headaches, with an odds ratio = 4.09) were common.49Nelson R. A systematic review of medical therapy for anal fissure.Dis Colon Rectum. 2004; 47: 422-431Crossref PubMed Scopus (114) Google Scholar Moreover, a subgroup analysis that excluded studies with low placebo response rates showed no significant benefit of nitroglycerin. Nitroglycerin has to be compounded for application, usually as a 0.2% ointment.Calcium channel blockers, nifedipine, and diltiazem have been studied in different studies, administered both orally and topically (0.2%-0.3% nifedipine and 2% diltiazem). In a Cochrane review analysis, there was no significant difference in efficacy compared with glyceryl trinitrate.47Nelson R. Non surgical therapy for anal fissure.Cochrane Database Syst Rev. 2006; (CD003431)Google Scholar Calcium channel blockers have shown fewer side effects than topical nitrates50Kocher H.M. Steward M. Leather A.J. et al.Randomized clinical trial assessing the side-effects of glyceryl trinitrate and diltiazem hydrochloride in the treatment of chronic anal fissure.Br J Surg. 2002; 89: 413-417Crossref PubMed Scopus (106) Google Scholar and have been found to be superior to topical lidocaine and hydrocortisone.51Antropoli C. Perrotti P. Rubino M. et al.Nifedipine for local use in conservative treatment of anal fissures: preliminary results of a multicenter study.Dis Colon Rectum. 1999; 42: 1011-1015Crossref PubMed Scopus (127) Google Scholar, 52Perrotti P. Bove A. Antropoli C. et al.Topical nifedipine with lidocaine ointment vs. active control for treatment of chronic anal fissure: results of a prospective, randomized, double-blind study.Dis Colon Rectum. 2002; 45: 1468-1475Crossref PubMed Scopus (90) Google Scholar A randomized study of 50 patients comparing topical with oral diltiazem showed topical to be more effective.53Jonas M. Neal K.R. Abercrombie J.F. et al.A randomized trial of oral vs. topical diltiazem for chronic anal fissures.Dis Colon Rectum. 2001; 44: 1074-1078Crossref PubMed Scopus (109) Google Scholar In a randomized, controlled trial comparing oral nifedipine and lateral anal sphincterotomy with tailored sphincterotomy, lateral anal sphincterotomy was associated with significantly better fissure healing rates (P < .001 at 16 weeks) and less recurrence (P = .003) than nifedipine.54Ho K.S. Ho Y.H. Randomized clinical trial comparing oral nifedipine with lateral anal sphincterotomy and tailored sphincterotomy in the treatment of chronic anal fissure.Br J Surg. 2005; 92: 403-408Crossref PubMed Scopus (22) Google Scholar There are no studies available that assess recurrence rates after 1 year. Given the limitations of oral and topical therapy, there has been considerable interest in botulinum toxin injection for chronic anal fissures. Botulinum toxin induces muscle relaxation by inhibiting the release of acetylcholine and is used in several spastic disorders. Reported healing rates with botulinum toxin injection vary widely, ranging from 37% to 92%.55Brisinda G. Maria G. Bentivoglio A.R. et al.A comparison of injections of botulinum toxin and topical nitroglycerin ointment for the treatment of chronic anal fissure.N Engl J Med. 1999; 341: 65-69Crossref PubMed Scopus (320) Google Scholar, 56Algaithy Z.K. Botulinum toxin versus surgical sphincterotomy in females with chronic anal fissure.Saudi Med J. 2008; 29: 1260-1263PubMed Google Scholar, 57Brisinda G. Cadeddu F. Brandara F. et al.Randomized clinical trial comparing botulinum toxin injections with 0.2 per cent nitroglycerin ointment for chronic anal fissure.Br J Surg. 2007; 94: 162-167Crossref PubMed Scopus (71) Google Scholar, 58Maria G. Cassetta E. Gui D. et al.A comparison of botulinum toxin and saline for the treatment of chronic anal fissure.N Engl J Med. 1998; 338: 217-220Crossref PubMed Scopus (290) Google Scholar The internal anal sphincter is palpated and, using a 27-gauge needle, a total of 20 U of botulinum toxin A is injected in divided doses in either side of the fissure.58Maria G. Cassetta E. Gui D. et al.A comparison of botulinum toxin and saline for the treatment of chronic anal fissure.N Engl J Med. 1998; 338: 217-220Crossref PubMed Scopus (290) Google Scholar When botulinum toxin was compared with nitroglycerin, botulinum toxin was more effective in fissure healing than nitroglycerin (92%-96% vs 60%-70%, respectively).55Brisinda G. Maria G. Bentivoglio A.R. et al.A comparison of injections of botulinum toxin and topical nitroglycerin ointment for the treatment of chronic anal fissure.N Engl J Med. 1999; 341: 65-69Crossref PubMed Scopus (320) Google Scholar, 57Brisinda G. Cadeddu F. Brandara F. et al.Randomized clinical trial comparing botulinum toxin injections with 0.2 per cent nitroglycerin ointment for chronic anal fissure.Br J Surg. 2007; 94: 162-167Crossref PubMed Scopus (71) Google Scholar Repeat injection may be beneficial in initial nonresponders or after relapse. Temporary, mild fecal incontinence and perianal thrombosis have been reported.59Jost W.H. Schimrigk K. Perianal thrombosis following injection therapy into the external anal sphincter using botulin toxin.Dis Colon Rectum. 1995; 38: 781Crossref PubMed Scopus (58) Google Scholar Long-term benefits and complications are unknown at this point.Surgical TreatmentSurgery has been superior to medical therapy in recent studies,60Nelson R. Non surgical therapy for anal fissure.Cochrane Database Syst Rev. 2006 Oct 18; (CD003431. Review)https://doi.org/10.1002/14651858.CD003431.pub2Crossref Google Scholar, 61Mishra R. Thomas S. Maan M. et al.Topical nitroglycerin versus lateral internal sphincterotomy for chronic anal fissure: prospective, randomized trial.ANZ J Surg. 2005; 75: 1032-1035Crossref PubMed Scopus (35) Google Scholar, 62Ho K.S. Ho Y.H. Randomized clinical trial comparing oral nifedipine with lateral anal sphincterotomy and tailored sphincterotomy in the treatment of chronic anal fissure.Br J Surg. 2005; 92: 403-408Crossref PubMed Scopus (46) Google Scholar, 63Iswariah H. Stephens J. Rieger N. et al.Randomized prospective controlled trial of lateral internal sphincterotomy versus injection of botulinum toxin for the treatment of idiopathic fissure in ano.ANZ J Surg. 2005; 75: 553-555Crossref PubMed Scopus (45) Google Scholar, 64Massoud B.W. Mehrdad V. Baharak T. et al.Botulinum toxin injection versus internal anal sphincterotomy for the treatment of chronic anal fissure.Ann Saudi Med. 2005; 25: 140-142PubMed Google Scholar, 65Parellada C. Randomized, prospective trial comparing 0.2 percent isosorbide dinitrate ointment with sphincterotomy in treatment of chronic anal fissure: a two-year follow-up.Dis Colon Rectum. 2004; 47: 437-443Crossref PubMed Scopus (40) Google Scholar with high healing and low relapse rates. Lateral internal sphincterotomy involves incising the internal anal sphincter through the skin of the lateral aspect of the anus, away from the anterior and posterior midline to reduce sphincter tone. Mean healing/improve