Practice Parameters for the Management of Anal Fissures (3rd Revision)

W. Brian Perry, M.D. • Sharon L. Dykes, M.D. • W. Donald Buie, M.D.
Janice F. Rafferty, M.D., on behalf of the Standards Practice Task Force of the
American Society of Colon and Rectal Surgeons

The American Society of Colon and Rectal Surgeons is dedicated to ensuring highquality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Standards Committee is composed of Society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive, and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than to dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed toward obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient.

Statement of the Problem
An anal fissure is an oval, ulcer like, longitudinal tear in the anal canal, distal to the dentate line. In almost 90% of cases, fissures are identified in the posterior midline, but can be seen in the anterior midline in up to 25% of affected women and 8% of affected men. Fissures occurring inlateral positions should raise suspicions for other disease processes, such as Crohn’s disease, tuberculosis, syphilis,HIV/AIDS, dermatologic conditions (psoriasis), or anal carcinoma. Early or acute fissures have the appearance of a simple tear in the anoderm, whereas chronic fissures, defined by symptoms lasting more than 8 to 12 weeks, are further characterized by edema and fibrosis. Typical inflammatory manifestations of chronic fissures include a sentinel skin tag at the distal fissure margin and a hypertrophied anal papilla proximal to the fissure in the anal canal. In addition, fibers of the internal anal sphincter are often visible at the fissure base. The clinical hallmark of ananal fissure is pain during, and particularly after, defecation. Often there is a history of a tearing sensation during passage of a constipated stool or with explosive diarrhea. Rectal bleeding, usually limited to minimal bright red blood on the toilet tissue, is not uncommon.

These guidelines are built on the last set of the American Society of Colon and Rectal Surgeons Practice Parametersfor treatment of Fissureinano published in 2004. An organized search of MEDLINE, Pubmed, EMBASE, and the Cochrane Database of Collected Reviews was performed through June 2009. Keyword combinations included anal fissure and fissure in ano as primary search terms. Directed searches were obtained from the latest dated reference from the previous version of the parameter to December 2008. The newest data were evaluated to see whether recommendations needed upgrading or downgrading with the additional information. Directed searches of the embedded references from the primary articles were alsoper formed in selected circumstances. The final grade of recommendation was performed using the Grades of Recommendation, Assessment, Development, and Evaluation(GRADE) system (Table 1).


    1. Nonoperative treatment continues to be safe, has few side effects, and should usually be the first step in therapy. Grade of Recommendation: Strong recommendation based on moderate quality evidence 1B

Almost half of all patients in whom an acute anal fissure has been diagnosed will heal with nonoperative measures, ie, sitz baths, psyllium fiber and bulking agents, with or without the addition of topical anesthetics or anti-inflammatory ointments. 1– 6 In addition to fissure healing, symptomatic relief of pain and bleeding can be achieved with virtually no side effects.

    2. Anal fissures may be treated with topical nitrates, although nitrates are marginally superior to placebo with regard to healing. Grade of Recommendation: Strong recommendation based on high-quality evidence 1A

Topical nitric oxide donors have been associated with healing in at least 50% of treated chronic fissures, 7–13,18 –21 and use of topical nitroglycerin significantly decreases pain during the therapy period. 7,9,16 An updated Cochrane review of medical treatment of anal fissures has concluded, however, that topical nitroglycerin remains only marginally better than placebo in healing anal fissures. 22 Dose escalation does not improve healing rates. 7,14,16 The principal side effect is headache, occurring in at least 20% to 30% of treated patients. 7,17,22 This adverse effect is dose-related and causes cessation of therapy in up to 20% of patients. 15 The incidence of fissure recurrence after treatment with topical nitric oxide donors is dramatically higher 7,8 compared with outcomes after surgery, although morbidity is lower. 8,10,12 Patients who do not respond to topical nitrates should be referred for botulinum toxin injections or surgery. 7,8,10

    3. Anal fissures may be treated with topical calcium channel blockers, with a lower incidence of adverse effects than topical nitrates. There are insufficient data to conclude whether they are superior to placebo in healing anal fissures. Grade of Recommendation: Strong recommendation based on moderate-quality evidence 1B

Topical calcium channel blockers have been associated with healing of chronic anal fissures in 65% to 95% of patients. 24 –31 Side effects include headache, in up to 25% of patients, 29 and occur less frequently than with topical nitrates. 27–29 There are still fewer randomized controlled trials of topical calcium channel blockers than of topical nitric oxide donors. Anal fissures may also be treated with oral calcium channel blockers. 32–35 This is associated with a lower rate of fissure healing than topical application and has a higher incidence of side effects. 32 Few direct comparisons of topical and oral calcium channel blockers exist.

    4. Botulinum toxin injection has been associated with healing rates superior to placebo. There is inadequate consensus on dosage, precise site of administration, number of injections or efficacy. Grade of Recommendation: Strong recommendation based on low-quality evidence 1C

Injection of botulinum toxin into the internal anal sphincter allows healing in 60% to 80% of fissures, 36,39,41,43,45,46 and at a higher rate than placebo. 42 The most common side effects are temporary incontinence to flatus in up to 18% of patients 38,39,42,45 and stool in 5%. 49 Recurrences may occur in up to 42% of cases, 38,39,46,47 but patients may be re-treated with a good rate of healing. 39,44 Higher doses are associated with improved rates of healing and are as safe as lower doses. 39,44 Topical nitrates appear to potentiate the effects of botulinum toxin in patients with refractory anal fissure. 37,48 There is no consensus on dose, site, or number of injections. 40,47 Patients in whom botu linum toxin injection therapy fails should be recommended for surgery. 40
There are few reports regarding the use of gonyautoxins for treatment of anal fissure. We have intentionally not included this treatment modality because of the paucity of data and the widespread unavailability of these agents.

    5. Lateral internal sphincterotomy is the surgical treatment of choice for refractory anal fissures. Grade of Recommendation: Strong recommendation based on high-quality evidence 1A

Lateral internal sphincterotomy (LIS) remains the surgical treatment of choice for refractory anal fissures. 22,49 Multiple studies 50 –53 and a recent Cochrane re view 54 show that LIS is superior to uncontrolled manual anal dilation, yielding superior healing rates with less incontinence. Controlled pneumatic balloon dilation has shown promise in one small series. 55 LIS offers superior healing and lower incontinence rates compared with posterior sphincterotomy-fissurectomy alone. 56 The addition of topical nitric oxide donors 57 or botulinum toxin 58–60 improves results of fissurectomy in nonrandomized series.

    6. Open and closed techniques of lateral internal sphincterotomy (LIS) yield similar results. Grade of Recommendation: Strong recommendation based on highquality evidence 1A

Further well-done studies confirm the prior assertion that there is no difference in outcomes between properly performed open or closed sphincterotomy. 54,61– 64

    7. LIS tailored to fissure characteristics yields equivalent or worse healing rates, and less incontinence, than traditional LIS to the dentate line. Grade of Recommendation: Weak recommendation based on moderate equality evidence 2B

A “tailored sphincterotomy” has been proposed in an effort to reduce the rate of minor incontinence following LIS. Two methods are typically employed—sphincterotomy only to the apex of the fissure or anal calibration. Three randomized trials of traditional vs fissure apex sphincterotomy show statistically superior healing rates in the traditional arm; 2 reported worse continence in the traditional arm, 65,66 whereas one did not. 67 To improve these results, a calibrated sphincterotomy has been reported. In these studies, fissure apex sphincterotomy was compared with a sphincterotomy that was extended based on the amount of residual anal stenosis remaining by use of a calibrated sound. In 3 small series, this method showed equivalent healing and lower incontinence rates than traditional sphincterotomy. 68 –70

    8. Anal advancement flap and subcutaneous fissurotomy are surgical alternatives to LIS. Grade of Recommendation: Weak recommendation based on low-quality evidence 2C

Techniques that do not divide the internal anal sphincter yet allow good healing rates are theoretically attractive, especially in patients with preexisting continence problems or in those without internal anal sphincter hypertonia. Small series of various anal advancement flaps show promise. 71,72 One series of unroofing subcutaneous sinuses associated with typical anal fissures reported excellent healing without changes in continence. 73 Larger trials in this area are still needed.

    9. Surgery is consistently superior to medical therapy and may be offered without a pharmacological treatment failure. Grade of Recommendation: Strong recommendation based on high-quality evidence 1A

Multiple trials continue to confirm the superiority of LIS to any topical or injected agent with low rates of incontinence. 10,46,74 –78 Most investigations show that compliance with long-term medical therapy remains an issue. The Cochrane Collaboration analyses of both surgical and nonsurgical therapies for anal fissure confirm these conclusions. 22,54 Quality of life (QOL) is poor in patients with persistent fissure, whereas patients undergoing LIS report significantly improved QOL. Fecal continence QOL is preserved in the vast majority of patients following LIS. 79–81
The practice parameters set forth in this document have been developed from sources believed to be reliable. The American Society of Colon and Rectal Surgeons makes no warranty, guarantee, or representation whatsoever as to the absolute validity or sufficiency of any parameter included in this document, and the Society assumes no responsibility for the use of the material contained.

Appendix A: Contributing Members Of The ASCRS Standards Committee
Farshid Araghizadeh, M.D., Robin Boushey, M.D., Sridhar Chalasani, M.D., George Chang, M.D., Robert Cima, M.D., Gary Dunn, M.D., Daniel Feingold, M.D., Philip Fleshner, M.D., Daniel Geisler, M.D., Jill Genua, M.D., Sharon Gregorcyk, M.D., Daniel Herzig, M.D., Andreas Kaiser, M.D., Ravin Kumar, M.D., David Larson, M.D., Steven Mills, M.D., John Monson, M.D., P. Terry Phang, M.D., Feza Remzi, M.D., David Rivadeneira, M.D., Howard Ross, M.D., Peter Senatore, M.D., Elin Sigurdson, M.D., Thomas Stahl, M.D., Scott Steele, M.D., Scott Strong, M.D., Charles Ternent, M.D., Judith Trudel, M.D., Madhulika Varma, M.D., Martin Weiser, M.D.
Recommendation 1
1. Gough MJ, Lewis A. The conservative treatment of fissure-in-ano.Br J Surg. 1983;70:175–176.
2. Jensen SL. Treatment of first episodes of acute anal fissure: pro spective randomised study of lignocaine ointment versus hydrocortisone ointment or warm sitz baths plus bran. BMJ. 1986;292: 1167–1169.
3. Shub HA, Salvati EP, Rubin RJ. Conservative treatment of anal fissure: an unselected, retrospective and continuous study. Dis Colon Rectum. 1978;21:582–583.
4. Hananel N, Gordon PH. Re-examination of clinical manifestations and response to therapy of fissure-in-ano. Dis Colon Rectum. 1997;40:229 –233.
5. Jensen SL. Maintenance therapy with unprocessed bran in the prevention of acute anal fissure recurrence.J R Soc Med. 1987; 80:296 –298.
6. Gupta P. Randomized, controlled study comparing sitz-bathand no-sitz-bath treatments in patients with acute anal fissures.ANZ J Surg.2006;76:718 –721.
Recommendation 2
7. Evans J, Luck A, Hewett P. Glyceryl trinitrate vs. lateral sphinc-terotomy for chronic anal fissure: prospective, randomized trial.Dis Colon Rectum.2001;44:93–97.
8. Kennedy ML, Sowter S, Nguyen H, Lubowski DZ. Glyceryl trini-trate ointment for the treatment of chronic anal fissure: resultsof a placebo-controlled trial and long-term follow-up. Dis ColonRectum.1999;42:1000 –1006.
9. Libertiny G, Knight JS, Farouk R. Randomised trial of topical 0.2% glyceryl trinitrate and lateral internal sphincter otomy for the treatment of patients with chronic anal fissure: long-termfollow-up. Eur J Surg.2002;168:418 – 421.
10. Lund JN, Scholefield JH. Glyceryl trinitrate is an effective treat-ment for anal fissure. Dis Colon Rectum.1997;40:468 – 470.
11. Oettle GJ. Glyceryl trinitrate vs. sphincterotomy for treatment ofchronic fissure-in-ano: a randomized, controlled trial.Dis ColonRectum.1997;40:1318 –1320.
12. Werre AJ, Palamba HW, Bilgen EJ, Eggink WF. Isosorbide dini-trate in the treatment of anal fissure: a randomized, prospective,double blind, placebo-controlled trial. Eur J Surg.2001;167:382–385.
13. Scholefield JH, Bock JU, Marla B, et al. A dose finding study with0.1%, 0.2%, and 0.4% glyceryl trinitrate ointment in patients with chronic anal fissures.Gut.2003;52:264 –269.
14. Zuberi BF, Rajput MR, Abro H, Shaikh SA. A randomized trialof glyceryl trinitrate ointment and nitroglycerin patch in healingof anal fissures. Int J Colorectal Dis.2000;15:243–245.
15. Bailey HR, Beck DE, Billingham RP, et al. Fissure Study Group. A study to determine the nitroglycerin ointment dose and dosing interval that best promote the healing of chronic anal fis-sures.Dis Colon Rectum. 2002; 45:1192–1199.
16. Altomare DF, Rinaldi M, Milito G, et al. Glyceryl trinitrate forchronic anal fissure— healing or headache? Results of a multi-center, randomized, placebo-controlled, double-blind trial. DisColon Rectum.2000;43:174 –181.
17. Lysy J, Israelit-Yatzkan Y, Sestiere-Ittah M, Keret D, Goldin E.Treatment of chronic anal fissure with isosorbide dinitrate: long-term results and dose determination.Dis Colon Rectum.1998;41:1406 –1410.
18. Lysy J, Israeli E, Levy S, Rozentzweig G, Strauss-Liviatan N, Gol-din E. Long-term results of “chemical sphincterotomy” forchronic anal fissure: a prospective study.Dis Colon Rectum.2006;49:858 – 864.
19. Lund JN, Scholefield JH. A randomised, prospective, double-blind, placebo-controlled trial of glyceryl trinitrate ointment in-treatment of anal fissure [published correction appears inLan-cet. 1997;349:656].Lancet. 1997;349:11–14.
20. Chaudhuri S, Pal AK, Acharya A, et al. Treatment of chronic analfissure with topical glyceryl trinitrate: a double-blind, placebo-controlled trial.Indian J Gastroenterol. 2001;20:101–102.
21. Bacher H, Mischinger HJ, Werkgartner G, et al. Local nitroglyc-erin for treatment of anal fissures: an alternative to lateral sphincter otomy? Dis Colon Rectum.1997;40:840 – 845.
22. Nelson R. Non surgical therapy for anal fissure. Cochrane Data-base Syst Rev. 2006;CD003431.
Recommendation 3
23. Shrivastava UK, Jain BK, Kumar P, Saifee Y. A comparison of the effects of diltiazem and glyceryl trinitrate ointment in the treat-ment of chronic anal fissure: a randomized clinical trial.SurgToday.2007;37:482– 485.
24. Carapeti EA, Kamm MA, Phillips RK. Topical diltiazem and bethanechol decrease anal sphincter pressure and heal anal fissures without side effects. Dis Colon Rectum.2000;43:1359 –1362.
25. Knight JS, Birks M, Farouk R. Topical diltiazem ointment in the treatment of chronic anal fissure. Br J Surg.2001;88:553–556.
26. Ezri T, Susmallian S. Topical nifedipine vs. topical glyceryl trini-trate for treatment of chronic anal fissure. Dis Colon Rectum.2003;46:805– 808.
27. Bielecki K, Kolodziejczak M. A prospective randomized trial ofdiltiazem and glyceryl trinitrate ointment in the treatment of chronic anal fissure. Colorectal Dis.2003;5:256 –257.
28. Kocher HM, Steward M, Leather AJ, Cullen PT. 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– 417.
29. Perrotti P, Bove A, Antropoli C, et al. Topical nifedipine with lidocaine ointment vs. active control for treatment of chronicanal fissure: results of a prospective, randomized, double-blindstudy. Dis Colon Rectum.2002;45:1468 –1475.
30. Antropoli C, Perrotti P, Rubino M, et al. Nifedipine for local use in conservative treatment of anal fissures: preliminary results ofa multicenter study.Dis Colon Rectum.1999;42:1011–1015.
31. Jonas M, Neal KR, Abercrombie JF, Scholefield JH. A random-ized trial of oral vs. topical diltiazem for chronic anal fissures. Dis Colon Rectum.2001;44:1074 –1078.
32. Ansaloni L, Bernabe` A, Ghetti R, Riccardi R, Tranchino RM, Gardini G. Oral lacidipine in the treatment of anal fissure.TechColoproctol.2002;6:79 – 82.
33. Ag aog lu N, Cengiz S, Arslan MK, Turkyilmaz S. Oral nifedipinein the treatment of chronic anal fissure.Dig Surg.2003;20:452–456.
34. Cook TA, Humphreys MM, Mortensen NJ. Oral nifedipine re-duces resting anal pressure and heals chronic anal fissure.Br JSurg.1999;86:1269 –1273.
Recommendation 4
35. Brisinda G, Cadeddu F, Brandara F, Marniga G, Maria G. Randomized clinical trial comparing botulinum toxin injectionswith 0.2 per cent nitroglycerin ointment for chronic anal fissure.Br J Surg.2007;94:162–167.
36. Jones OM, Ramalingam T, Merrie A, et al. Randomized clinicaltrial of botulinum toxin plus glyceryl trinitrate vs. botulinumtoxin alone for medically resistant chronic anal fissure: overallpoor healing rates.Dis Colon Rectum.2006;49:1574 –1580.
37. Arroyo A, Perez F, Serrano P, Candela F, Calpena R. Longtermresults of botulinum toxin for the treatment of chronic analfissure: prospective clinical and manometric study. Int J Colorectal Dis.2005;20:267–271.
38. Brisinda G, Maria G, Sganga G, Bentivoglio AR, Albanese A,Castagneto M. Effectiveness of higher doses of botulinum toxinto induce healing in patients with chronic anal fissures.Surgery.2002;131:179 –184.
39. Maria G, Brisinda G, Bentivoglio AR, Cassetta E, Gui D, Albanese A. Influence of botulinum toxin site of injections onhealing rate in patients with chronic anal fissure.Am J Surg.2000;179:46 –50.
40. Brisinda G, Maria G, Bentivoglio AR, Cassetta E, Gui D, Albanese A. A comparison of injections of botulinum toxin andtopical nitroglycerin ointment for the treatment of chronic analfissure [published correction appears inN Engl J Med. 1999;341:624].N Engl J Med.1999;341:65– 69.
41. Maria G, Cassetta E, Gui D, Brisinda G, Bentivoglio AR, Albanese A. A comparison of botulinum toxin and saline for thetreatment of chronic anal fissure.N Engl J Med.1998;338:217–220.
42. Colak T, Ipek T, Kanik A, Aydin S. A randomized trial of botulinum toxin vs. lidocaine pomade for chronic anal fissure.ActaGastroenterol Belg.2002;65:187–190.
43. Madalinski MH, Slawek J, Zbytek B, et al. Topical nitrates andthe higher doses of botulinum toxin for chronic anal fissure.Hepatogastroenterology.2001;48:977–979.
44. Lindsey I, Jones OM, Cunningham C, George BD, MortensenNJ. Botulinum toxin as secondline therapy for chronic analfissure failing 0.2 percent glyceryl trinitrate.Dis Colon Rectum.2003;46:361–366.
45. Menteçs BB, Irkorucu O, Akin M, Leventoglu S, Tatlicioglu E.Comparison of botulinum toxin injection and lateral internalsphincterotomy for the treatment of chronic anal fissure. DisColon Rectum.2003;46:232–237.
46. Minguez M, Herreros B, Espi A, et al. Longterm followup (42months) of chronic anal fissure after healing with botulinumtoxin.Gastroenterology.2002;123:112–117.
47. Lysy J, IsraelitYatzkan Y, SestieryIttah M, et al. Topical nitratespotentiate the effect of botulinum toxin in the treatment of patients with refractory anal fissure.Gut.2001;48:221–224.
48. Jost WH. One hundred cases of anal fissure treated with botulinum toxin: early and longterm results. Dis Colon Rectum.1997;40:1029 –1032.
Recommendation 5
49. Richard CS, Greggoire R, Plewes EA, et al. Internal sphincterotomy is superior to topical nitroglycerine in the treatment of chronic anal fissure: results of a randomized, controlled trial by he Canadian Colorectal Surgical Trials Group.
Dis Colon Rectum. 2000;43:1048 –1047.
50. Jensen SL, Lund F, Nielsen OV, Tange G. Lateral subcutaneous sphincterotomy versus anal dilatation in the treatment of fissure in ano in outpatients: a prospective randomized study. BMJ. 1984;289:528 –530.
51. Saad AM, Omer A. Surgical treatment of chronic fissure in ano: a prospective randomized study. East Afr Med J . 1992;69:613– 615.
52. Olsen J, Mortensen PE, Krogh Petersen I, et al. Anal sphincter function after treatment of fissure-in-ano by lateral subcutaneous sphincterotomy versus anal dilation. Int J Colorectal Dis. 1987;2:155–157.
53. Weaver RM, Ambrose NS, Alexander-Williams J, et al. Manual dilation of the anus vs. lateral internal sphincterotomy in the treatment of chronic fissure-in-ano: results of a prospective, randomized clinical trial. Dis Colon Rectum. 1987;30:420 – 423.
54. Nelson R. Operative procedures for fissure in ano. Cochrane Database Syst Rev. 2005:CD002199.
55. Renzi A, Izzo D, Di Sarno G, et al. Clinical, manometric, and ultrasonographic results of pneumatic balloon dilatation vs. lateral internal sphincterotomy for chronic anal fissure: a prospective, randomized, controlled trial. Dis Colon Rectum. 2008;51: 121–127.
56. Abcarian H. Surgical correction of chronic anal fissure: results of lateral internal sphincterotomy vs. fissurectomy-midline sphincterotomy. Dis Colon Rectum. 1980;23:31–36.
57. Engel AF, Eijsbouts QA, Balk AG. Fissurectomy and isosorbide dinitrate for chronic fissure in ano not responding to conservative treatment. Br J Surg. 2002;89:79 – 83.
58. Baraza W, Boereboom C, Shorthouse A, et al. The long-term efficacy of fissurectomy and botulinum toxin injection for chronic anal fissure in females. Dis Colon Rectum. 2008;51:236 – 243.
59. Scholz T, Hetzer FH, Dindo D, et al. Long-term follow-up after combined fissurectomy and Botox injection for chronic anal fissures. Int J Colorectal Dis . 22:1077–1081.
60. Lindsey I, Cunningham C, Jones OM, et al. Fissurectomy-botulinum toxin: a novel sphincter-sparing procedure for medically resistant chronic anal fissure, Dis Colon Rectum. 2004;47:1947– 1952.
Recommendation 6
61. Boulous PB, Araujo JG. Adequate internal sphincterotomy for chronic anal fissure: subcutaneous or open technique? Br J Surg . 1984;71:360 –362.
62. Kortbeek JB, Langevin JM, Khoo RE, et al. Chronic fissure-inano: a randomized study comparing open and subcutaneous lateral internal sphincterotomy. Dis Colon Rectum. 1992;35:835– 837.
63. Arroyo A, Perez F, Serrano P, et al. Open versus closed lateral internal sphincterotomy performed as an outpatient procedure under local anesthesia for chronic anal fissure: prospective randomized study of clinical and manometric long-term results. J Am Coll Surg. 2004;199:361–367.
64. Wiley M, Day P, Rieger N, et al. Open vs. closed lateral internal sphincterotomy for idiopathic fissure-in-ano: a prospective, randomized, controlled trial. Dis Colon Rectum. 2004;47:847– 852.
65. Mentes BB, Ege B, Leventoglu S, et al. Extent of lateral internal 1114 P ERRY ET AL 😛 RACTICE P ARAMETERS FOR A NAL F ISSURES sphincterotomy: up to the dentate line or up to the fissure apex? Dis Colon Rectum. 2005;48:365–370.
Recommendation 7
66. Elsebae MM. A study of fecal incontinence in patients with chronic anal fissure: prospective, randomized, controlled trial of the extent of internal anal sphincter division during lateral sphincterotomy. World J Surg. 2007;31:2052–2057.
67. Ho KS, Ho KY. 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– 408.
68. Cho DY. Controlled lateral sphincterotomy for chronic anal fissure. Dis Colon Rectum. 2005;48:1037–1041.
69. Rosa G, Lolli P, Piccinelli D, et al. Calibrated lateral internal sphincterotomy for chronic anal fissure. Tech Coloproctol. 2005; 9:127–131.
70. Mentes BB, Guner MK, Leventoglu S, et al. Fine-tuning of the extent of lateral internal sphincterotomy: spasm-controlled vs. up to the fissure apex. Dis Colon Rectum. 2008;51:128 –133. Recommendation 8
71. Leong AF, Seow-Choen F. Lateral sphincterotomy compared with anal advancement flap for chronic anal fissure. Dis Colon Rectum. 1995;38:69 –71.
72. Singh M, Sharma A, Gardiner A, et al. Early results of a rotational flap to treat chronic anal fissures. Int J Colorectal Dis. 2005;20:339 –342.
73. Pelta AE, Davis KG, Armstrong DN. Subcutaneous fissurotomy: a novel procedure for chronic fissure-in-ano. A review of 109 cases. Dis Colon Rectum. 2007;50:1662–1667.
Recommendation 9
74. Arroyo A, Perez F, Serrano P, et al. Surgical versus chemical (botulinum toxin) sphincterotomy for chronic anal fissure: long-term results of a prospective randomized clinical and manometric study. Am J Surg . 2005;189:429 – 434.
75. Iswariah 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;75:553–555.
76. Katsinelos P, Papaziogas B, Koutelidakis I, et al. Topical 0.5% nifedipine vs. lateral internal sphincterotomy for the treatment of chronic anal fissure: long term follow-up. Int J Colorectal Dis. 2006;21:179 –183.
77. Brown CJ, Dubreuil D, Santoro L, et al. Lateral internal sphincterotomy is superior to topical nitroglycerine for healing chronic anal fissure and does not compromise long-term fecal incontinence: six year follow-up of a multicenter, randomized, controlled trial. Dis Colon Rectum. 2007;50:442– 448.
78. Sileri P, Mele A, Stolfi VM, et al. Medical and surgical treatment of chronic anal fissure: a prospective study. J Gastrointest Surg. 2007;11:1541–1548.
79. Hyman N. Incontinence after lateral internal sphincterotomy: a prospective study and quality of life assessment. Dis Colon Rectum . 2004;47:35–38.
80. Ortiz H, Marzo J, Armendariz P, et al. Quality of life assessment in patients with chronic anal fissure after lateral internal sphincterotomy. Br J Surg. 2005;92:881– 885.
81. Mentes BB, Tezcaner T, Yilmaz U. Results of lateral internal sphincterotomy for chronic anal fissure with particular reference to quality of life. Dis Colon Rectum. 2006;49:1045–1051