Causes, forms, treatment

Pain and bleeding during bowel movements

The most common cause of pain and bleeding during defecation is anal fissure, also called anal tear or anal fissure. This is the name given to a longitudinal tear in the transition zone of the tender skin of the anal canal (anoderm) to the outer skin. Anal fissure is one of the most common reasons why patients consult a proctologist.

Anal fissure is almost always a benign condition that is easily treated. The exact frequency is not known, because according to a representative survey, 87.5 % of people with anorectal complaints never see a doctor. Women seem to be affected slightly more often.

A distinction is made between the acute and the chronic form. Depending on the stage, conservative or surgical treatment methods are used.

Chronic anal fissure is a common cause of blood in the stool and of pain
Anatomical model of a chronic anal fissure with secondary changes (1 hypertrophic anal papilla, 2 deep crypts, 3 anal fissure, 4 outpost fold).

Mechanical and inflammatory causes

How does an anal fissure develop?

Cause of anal fissure: Hard stool

The mucous membrane of the anal canal can be affected and tear whenever the area is too stressed. A variety of different circumstances such as stress, unbalanced diet or antibiotic treatments can become the trigger for an anal fissure such as

  • Stool too hard (constipation)
  • diarrhoea
  • Too much pressing during bowel movement
  • Too much elongation of the area (anal intercourse)

Cause of anal fissure: cryptitis and subanodermal fistula

If the anal mucosa (anoderm) is already damaged, as in the case of enlarged haemorrhoids or inflammation of the anal glands (cryptitis), a chronic wound can occur even with normal bowel movements. These glands open into the small pockets (crypts, (2) in the illustration) at the transition from the intestinal mucosa to the anal skin. If the glands are inflamed, a superficial fistula tract can form under the anal skin, which then breaks open in the area of the fissure (3). 

Cause of anal fissure: High sphincter pressure?

The opinion that a pathologically increased sphincter pressure is the cause of anal fissure is widespread among doctors and in the specialist literature. The association of anal fissures with high sphincter pressure can be proven by pressure measurement (sphincter manometry). As a result, there is a reduction in blood flow, which in turn hinders healing.

In contrast, the muscle tension can also be explained as a consequence of the painful condition. It is rare to find high sphincter pressure without underlying pain. And when you see how much an anal fissure can bleed, you don't really believe in the reduced blood flow.

Conversely, this tension contributes to the wound edges being pressed together after the bowel movement is complete. Measures to relax can therefore help the wound to clean itself better and thus heal from the depths.

Cause of anal fissure: After operations

Wound healing disorders after anal surgery for other reasons, for example haemorrhoids or anal thrombosis, can also end in chronic wounds resembling a spontaneously developed chronic anal fissure. We see this as an argument to perform any surgery on the anus only if one has no (good) therapeutic alternative and the patient's level of suffering is high.

How you recognise the disease

Symptoms anal fissure

Out of the blue: Acute anal fissure

Acute anal fissure looks like a cut. Typically, an anal fissure is accompanied by a sharp or burning pain during defecation ("... as if there were a shard of glass in the stool..."). After defecation, this pain usually subsides quickly.

The second leading symptom is bright red, fresh bleeding. The intensity of the bleeding ranges from a trace of blood on the paper to dramatic-looking splashes of blood in the toilet. The actual blood loss is nevertheless small and not dangerous.

Many patients also only have either bleeding or pain and not both symptoms. Often the symptoms subside quickly without specific treatment and the initial shock is quickly forgotten.

The lowest extension of the acute anal fissure can usually be seen on examination when the buttocks are spread slightly. Almost all anal fissures are found in the midline and 75-90 % on the side facing the coccyx ("6 o'clock in lithotomy position SSL", i.e. on examination in the gynaecological chair). Patients often perceive the pain maximum accentuated towards the left side, even if the wound is in the centre.

Fissures lateral to the midline ("atypical fissures") must occasionally also suggest infections, including HIV, tuberculosis and syphilis, tumours and chronic inflammatory bowel diseases such as Crohn's disease. In this case, the guideline recommends "adapted further diagnostics with serological and microbiological examinations as well as a colonoscopy with biopsy removal".

Good times, bad times: Chronic anal fissure

If periods without symptoms alternate with periods when symptoms recur, the disease is likely to be chronic.

Also, if the pain is dull, delayed after defecation and lasts for hours, this indicates the development of a chronic anal fissure. Patients often report that the pain radiates towards the coccyx.

Other complaints that may develop in the course are itching, anal dampness, traces of blood on the toilet paper, constipation with incomplete emptying of the rectum and increased flatulence.

Externally visible signs of chronic anal fissure are skin thickening or skin folds called outpost fold or guardian mariske. Some patients feel a palpable hardening. Internal growths in the area of the anal papillae (1) are called hypertrophic papillae. These tissue proliferations are caused by local tissue hormones that are actually intended to help heal wounds.

In chronic anal fissure, it is not uncommon to see the exposed internal sphincter muscle at the bottom of the wound.

Since these typical symptoms also occur in other proctological diseases such as the coccyx fistula, an exact diagnosis of anal fissure is important.

Conservative or surgical?

Treatment anal fissure

Despite unfavourable conditions in the wound area (intestinal bacteria, constriction, moisture, mechanical stress), 75% of anal fissures surprisingly usually heal by themselves or with simple, caring measures such as relaxing sitz baths.

If pain and bleeding disappear quickly, the patient forgets the unpleasant episode and does not seek further clarification. It is not uncommon for the wound to be closed only superficially, but in the depth of the tear, chronic inflammation develops due to contamination with the ever-present intestinal bacteria.

If the scar is not stable and tears open again and again even in normal stools, outpost folds and growths of the mucous membrane (hypertrophic anal papilla) develop. These skin lobules are often thought to be a hemorrhoid or a polyp. They can assume considerable size and emerge from the anus. Over time, the niche can deepen more and more, in which stool particles and bacteria settle, which further irritate the mucous membrane.

Conservative therapy

Treatment of anal fissure without surgery

If an acute anal fissure has not been present for long, surgery can often be avoided. Studies have found a cure rate of 43 - 87 % with conservative treatment.

The goal is not too hard but still formed bowel movements. Ground psyllium husks (available e.g. as Fluxlon® or Mucofalk ® in pharmacies, but also from various manufacturers in drugstores and health food shops) have proven to be most effective. They swell on contact with liquids and thus soften hard stools and bind off stools that are too liquid. Psyllium husks have no taste of their own. Those who find it difficult to take them can stir them into yoghurt, milk, soy drinks or soups, or use psyllium capsules. The finely ground preparation of Flosa Balance® can also be an alternative.

 If psyllium husks do not work sufficiently, macrogol powder (e.g. Movicol®, Laxatan®, numerous generic manufacturers) is a reliable stool - softener.

The Sitz Bath is a classic of proctological treatment, so much so that it has even become a foreign word in English as "Sitz Bath". It allows gentle cleansing and is very pleasant due to its relaxing effect. Bath additives with synthetic tannins(Tannolact®) or camomile(Kamillosan®) are said to have an anti-inflammatory effect.

  • Topical nitrates (e.g. Rectogesic®) release nitric oxide (NO), which has a relaxing effect on the internal sphincter. In a collective statistic, this therapy principle was superior to the treatment with a placebo (37 %) with a healing rate of 49 %. Other studies showed a significant reduction in pain with nitrate ointment. The main side effects include headaches, which often lead to discontinuation of treatment. After discontinuation of the therapy, anal fissure recurs in up to 50 % of cases.
  • Calcium antagonists (nifedipine, diltiazem) also have a relaxing effect on the smooth muscles of the internal sphincter and improve blood flow. Various formulations, i.e. ointment preparations to be mixed by the pharmacist, are widely used. In prospective studies, healing rates of 68 % were found after 8 weeks of use. The main advantage of these substances over the literates is better tolerability. A formulation with diltiazem and lidocaine is the standard in our practice for the primary treatment of anal fissure.
  • Levorag® Emulgel: The effect of this class 1 medical product is based on the action of myoxinol, a plant extract from hibiscus with a Botox-like effect, and carboxymethyl glucan, a natural pullis of caritas hieven with an immunostimulating effect. In a comparative study with diltiazem ointment, the latter was superior in terms of pain relief and equivalent in terms of healing. Advantages are seen for patients who had an allergic reaction to diltiazem ointment.
  • Botulinum toxin(Botox): Thisneurotoxin produced by the bacterium Clostridium botulinum blocks the release of acetylcholine at the presynaptic nerve of the neuromuscular end plate. The effect is a temporary paralysis of the internal sphincter for about 3 months. The dose described is 40-100 units. The effect is roughly comparable to the ointments described above, with 20-30 units of Botox® being equivalent to 60-90 units of Dysport®. Cure rates of up to 75 % with a recurrence rate of up to 42 % are reported. The application is limited by the high price, the lack of coverage by public health insurances and uncertainties regarding the optimal dose. Too high doses lead to incontinence, too low doses do not help. We ourselves have no experience with this drug. Overall, the euphoria among experts regarding this treatment option has subsided somewhat in recent years.

These sites are used very frequently; especially in the acute painful phases, they can provide good relief from the symptoms. The best-known representatives of this genus include DoloPosterine®, Posterisan akut®, Factu akut® and Haenal® akut. These preparations contribute little or nothing to healing.

The use of laser light has been known for a long time for typical problem wounds such as the diabetic foot and the lower leg ulcer (Ulcus cruris) in venous disorders.

A variety of cellular mechanisms of action have been experimentally demonstrated: Anti-inflammation, stimulation of growth factors, improvement of connective tissue stability as well as microcirculation and cellular metabolic activity. It therefore stands to reason that these mechanisms can also promote the healing of an anal fissure.

LLLT is a treatment modality for anal fissure that has not yet been systematically investigated and which we have copied from wound treatment for other indications. It is painless and non-invasive and leads to at least temporary freedom from symptoms in the majority of patients treated so far. We have not done any long-term studies. Due to the sparse data available, this treatment modality is not recognised as a health insurance benefit. We usually carry out five treatments for 40 € each. I see this treatment as an alternative if the proven therapy with ointment and stool regulation does not help sufficiently.

When to operate and how?

Operations for chronic anal fissure

When should surgery be considered for anal fissure? The statistical chances of healing under conservative therapy are very low if

  • Conservative treatment with stool regulation and one of the ointments mentioned has been carried out consistently for 8 weeks without a lasting cure having occurred
  • there is very severe pain that is delayed after defecation and then lasts for hours or even the whole day
  • the frequency or intensity of bleeding increases over time
  • permanent or recurring complaints for six months or more
  • If there are secondary changes: outpost fold, hypertrophic anal papilla

The chance of healing without surgery drops to zero if the inflammation in the base of the fissure has worked its way through the anal verge, creating a festive one.

Another important, if not the most important, criterion for deciding on an operation is the patient's subjective level of suffering. If you are already afraid of every bowel movement and would prefer not to go to the toilet at all, it will be easier to decide on an operation than if you manage well with ointment and stool regulation.

Rarely, a reason for an operation can also result from the fact that one is uncertain about the benignity of the visible changes and a removal for fine tissue examination is necessary.

Excision of the anal fissure (fissurectomy according to Gabriel)

The purpose of the so-called fissurectomy is to make a deep wound into a shallow one and to eliminate any kind of pocket or niche formation. Then the wound can heal from the depth and long-term freedom from symptoms can be expected. This procedure is always done under anaesthesia so that an anal fistula, which sometimes develops at the same time or as a result of the anal fissure, is not overlooked. Most surgeons perform this operation with an electric scalpel to avoid the bleeding tendency that is pronounced in the anal region.

Laser fissurectomy

The operation with the diode laser (980 nm Intros Lina or 1479 nm Biolitec Ceralas) has a number of advantages over the standard operation.

  • Tissue protection: there is no current flow through the tissue and the thermal collateral damage, i.e. the impairment of the neighbouring tissue by heat, is significantly lower than with the electric scalpel.
  • Precision: Laser energy has a very focused effect and thus allows unrivalled accuracy in the incision. Because minor bleeding is automatically stopped, the surgeon has an optimal view of the treatment area.
  • Promotion of wound healing: The healing-promoting stimulation of the surrounding tissue comparable to the effect in LLLT by the laser light is a "desired side effect" of laser surgery.

Severing the internal sphincter muscle (lateral sphincterotomy)

In this operation, the internal sphincter ring is cut laterally ("laterally"). A distinction is made between open sphincterotomy, in which the corresponding sphincter function is first exposed, and closed sphincterotomy, in which the severance is performed without direct vision, controlled only by the palpating finger.

An American review from 2018 describes lateral sphincterotomy as the gold standard in the treatment of chronic anal fissure. The high healing rate of 95 % is listed as justification for this view. At the same time, a limitation of control for intestinal gas (incontinence for flatus) and fluid (soiling) and for stool of 1% is mentioned with a number of cases in the study of 4500 patients. Other investigators found incontinence of varying degrees in up to 60%. 

In accordance with the current German guideline Anal Fissure, I cannot share this opinion. I consider the rate of incontinence, which will probably even increase with longer observation time, i.e. aging patients, to be unacceptable and therefore do not perform this operation.

Cutting out the fissure and covering it with a local displacement flap (Advance-Flap)

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CO2 laser vaporisation and treatment of the fissure base and sphincter with the fractionated ("rejuvenation") laser

A publication from Iran by Esfahani describes the ablation of secondary lesions with the ablative CO2 laser and the treatment of the wound area with the fractional laser. This modality is used in aesthetic laser surgery for skin tightening. The authors postulate an LLLT-like effect on wound healing. Pain, bleeding and itching were significantly reduced by this treatment with very good patient satisfaction. Incontinence or recurrences were not described.

Anal fissure: specialist literature

  1. Boland, P. A., Kelly, M. E., Donlon, N. E., Bolger, J. C., Larkin, J. O., Mehigan, B. J., & McCormick, P. H. (2020). Management options for chronic anal fissure: a systematic review of randomised controlled trials. International journal of colorectal disease, 35(10), 1807-1815.
  2. Brisinda, G., Vanella, S., Crocco, A., & Maria, G. (2012). Type A botulinum toxin treatment for chronic anal fissure. International Journal of Colorectal Disease, 27(11), 1543-1545.
  3. (1869). On Anal Fissure. The British and Foreign Medico-Chirurgical Review, 44(87), 178-180.
  4. Carlson, N., Theal, R., & Marshall, R. (2013). Anal fissure. Evidence-Based Practice, 16(1)
  5. Esfahani, M., Madani, G., & Madhkhan, S. (2015). A novel method of anal fissure laser surgery: a pilot study. Lasers in Medical Science, 30(6), 1711-1717.
  6. Garg, P. (2020). Anal fistula associated with anal fissure. Techniques in Coloproctology, 24(7), 785-785.
  7. Hopkins JT, McLoda TA, Seegmiller JG, David Baxter G. Low-Level Laser Therapy Facilitates Superficial Wound Healing in Humans: A Triple-Blind, Sham-Controlled Study. J Athl Train. 2004 Sep;39(3):223-229. PMID: 15496990; PMCID: PMC522143.
  8. Kirsch, J. (2004). Anal fissure. Wiener Medizinische Wochenschrift, 154(4), 69-72.
  9. Lu, Y., Kwaan, M., & Lin, A. (2021). Diagnosis and Treatment of Anal Fissures in 2021. JAMA, 325(7), 688-689.
  10. (2007). Anal Fissure. Colorectal Website Review. Diseases of the Colon & Rectum, 50(8), 1280-1284.
  11. Nelson, R. L., Thomas, K., Morgan, J., & Jones, A. (2012). Non-surgical therapy for anal fissure. The Cochrane database of systematic reviews, 2012(2), CD003431.
  12. Nordholm-Carstensen, A., Perregaard, H., Wahlstrøm, K., Hagen, K., Hougaard, H., & Krarup, P. (2020). Treatment of chronic anal fissure: a feasibility study on Levorag® emulgel versus Diltiazem gel 2%. International Journal of Colorectal Disease, 35(4), 615-621.
  13. Schouten, W., Briel, J., Auwerda, J., & de Graaf, E. (1996). Ischaemic nature of anal fissure. British Journal of Surgery, 83(1), 63-65.
  14. Steinhagen, E. (2018). Anal fissure. Diseases of the Colon & Rectum, 61(3), 293-297.
  15. Sugerman, D. (2014). Anal fissure. JAMA, 311(11), 1171-1171.


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