Anal fissure

Overview: dentate line anal fissure is a full-thickness skin small ulcers. Its longitudinal axis parallel to the direction of the anal canal, about 0.5 ~ 1.0cm, spindle-shaped or oval, healing difficulties, is the young people have a common cause of pain at the anal canal. The anal fissure can not be considered superficial laceration, because soon heal, and often asymptomatic. After anal fissure occurs in the office, if there is side anal fissure, or there are multiple cracks, should be thought of inflammatory bowel disease may be an early manifestation.

anal fissure is caused by what the?

shorter period of onset of acute anal fissure, the color red, the bottom light, rip fresh, clean, no scar formation. longer course of chronic anal fissure, repeated seizures, irregular deep end, often the top mast nipple, the bottom often sentinel hemorrhoid, anal fissure is generally known as the "triad." Sentinel lymph node is due to hemorrhoids caused by cholestasis in the skin, like external hemorrhoids, due to this check, for hemorrhoids and then look to see cracks, the diagnosis of help, so called sentinel hemorrhoid or fissure hemorrhoids. Also in advanced concurrent perianal subcutaneous abscess and anal fistula.

(a) causes

the exact cause of anal fissure is not yet clear, the following factors and the occurrence of anal fissure :

1. anatomical factors superficial anal sphincter in the anal anal tail behind the formation of ligaments, more rigid, scalability is poor; most attached to the levator ani muscle on both sides of the anal canal , so the anal canal on both sides of the front and rear as a strong, easy to damage; the anal canal and rectum to form the anorectal angle, anal canal so that the back pressure to bear droppings are all factors that cause anal fissure.

2. trauma patients with chronic constipation, the stool dry and hard, too much force when defecating, easy to damage the anal skin, repeated injury to the deep and full-thickness skin laceration, the formation of chronic infection of the ulcer. It was reported that constipation caused by anal fissure, 14% to 24%, but constipation may also be consequences of anal fissure is due to the patient due to fear of defecation. In addition, birth trauma can also cause anal fissure, about 3% to 9%. Diarrhea, frequent bowel movements, anal contraction is also easy to damage the sensitive, repeated injury chronic infections ulcers.

3. dentate line in the vicinity of infected chronic inflammation, such as sinusitis after middle at the anus, spread down the walls of subcutaneous abscess, ulceration and a chronic ulcer; anal tube hardly healing after injury is still unknown reasons, some people think it is mainly due to injury and infection, infection, inflammatory cells can release soluble collagenase, prevent epithelial tissue regeneration and extension.

4. ischemia was made recently after a midline anal fissure occurs in ischemia there is a reason, because the distal anal canal by rectal artery The blood vessels through the ischial rectal fossa, the separation of a small branch to the mucous membrane through the anal sphincter, but most lack the rectum after the joint at the branch artery (85%). Study also suggested from the capillary morphology at the midline of the capillaries within the internal sphincter sparse. Some applications of laser Doppler measured blood flow at the anal canal after the joint Department for less than the other quadrants. Described above are the incidence of ischemia is indeed a major factor of chronic anal fissure.

5. anal canal stenosis congenital malformations, trauma or surgery due to anal stenosis, in the dry manure will easily damaged by the occurrence of anal fissure.

6. fissure within the tight sphincter in patients with abnormal sphincter excessive shrinkage. reflex spasm of the internal sphincter is currently considered an important reason for difficult to heal anal fissure. anal fissure in patients with anal canal pressure was significantly higher than normal, reaching 127.5 ± 42.2kPa (956 ± 316mmHg), while the normal is only 86.3 ± 33.3kPa (647 ± 250mmHg). After this high-pressure in the anal recover to near normal after treatment.

(B) the pathogenesis

1. good site anal fissure is often a gap, the vast majority in After the anal canal in line. Reported 355 cases of anal fissure in foreign countries, 89% in the posterior midline at 7% in the middle at the front, sides and front office are located in each of 2%. More common in women before the middle of the penalty.

2. pathologic shorter onset of acute anal fissure, the color red, the bottom light, rip fresh, clean, and no scar formation. Longer duration of chronic anal fissure, repeated seizures, irregular deep end, often the top nipple hypertrophy, the bottom often sentinel hemorrhoids, anal fissure is generally known as the "triad" (Figure 1). Sentinel lymph node is due to hemorrhoids caused by deposition in the skin, like external hemorrhoids, due to this check, for hemorrhoids and then look to see cracks, the diagnosis of help, so called sentinel hemorrhoid or fissure hemorrhoids. Also in advanced concurrent perianal subcutaneous abscess and anal fistula.

3. classification of the classification of the disease has not been uniform at home and abroad, there are two commonly used clinical classification and the three classifications.

(1) 2 be classified and method: ① early anal fissure (acute phase): rip fresh, without the formation of chronic ulcers, less pain; ② chronic anal fissure (chronic period): rip has formed a chronic ulcer, while hypertrophy of anal papillae, skin down, etc., severe pain.

(2) 3 be classified and: ① Ⅰ period of anal fissure: a short duration, bottom ulcer clean, soft, no complications; ② Ⅱ period of anal fissure: ulcer base was gray, irregular thickening of the edge, hard or creeping, anal flexible weakened, there are complications; ③ Ⅲ period of anal fissure: fissure ulcers, such as 2. anal fibrosis, stenosis, ulcers have a direct impact on the severity of complications.

what the early symptoms of anal fissure?

anal fissure patients with typical clinical manifestations of pain, constipation and blood in the stool.

1. defecation pain, anal fissure may be caused by cyclical pain, which is the main symptom of anal fissure. Defecation, the fecal material to stimulate the nerve endings of ulcers, and immediately felt a burning anus, pain relief, but then after a few minutes, this period of said intermittent pain. Later due to sphincter spasm, and produce pain, this term sustainability and a half hours to a few hours, the patient restless, difficult to endure, until the sphincter fatigue, muscle relaxation, pain relief. But again, defecation, and pain occurs. More clinical as anal fissure pain cycle. pain can also radiate to the perineum, buttocks, inner thigh or sacral.

2. constipation and this is the cause of anal fissure, but also the consequences of anal fissure. anal fissure pain after the patient was reluctant to defecate, over time lead to constipation, hard stool more dry, constipation and anal fissure can increase, creating a vicious cycle, so difficult to heal anal fissure.

3. blood in the stool or bowel movement is often the surface of the stool will see a small amount of fresh blood on paper, or drops of blood. bleeding rare.

4. others such as anal itching, discharge, and diarrhea. ulcers due to anal fissure anal crypt secretions or concurrent inflammation, anal secretions produced go far nipple stimulation, causing anal itching (Table 1).

5. signs abroad have reported 355 cases of anal fissure different signs of the following: 78% of anal spasm, sentinel hemorrhoids 68%, 25% of papillary hypertrophy, anal fistula, 6%, intersphincteric abscess 4%, 38% of hemorrhoids, anal stenosis in 2%.

more general history of constipation. Asked whether the defecation defecation pain history and the history, the more they have the typical intermittent pain and pain cycle. Local examination found after the middle part of the anal fissure "triad", the diagnosis clear. chronic ulcers located lateral to think of any tuberculosis, cancer, crohn's disease and ulcerative colitis and other rare diseases, where necessary, line of biopsy.

ate anal fissure?

anal fissure diet (The following information is for reference only, details need to consult a doctor)

side 1 purslane radish seed drink

composition: 20 g of purslane, radish seed 10 grams.

Usage: purslane, radish seeds were washed, set the pot, add 500 ml of water, emergency heat and simmer for opening three minutes Simmer for 20 minutes, residues juice, were taken.

effect: detoxification, purge intestines.

Indications: the initial issuance of anal fissure, anal swelling were.

side 2 dandelion rice

consists of: dandelion 20 grams, 50 grams of rice.

Usage: dandelion washed, cut into fine, set the pot, add 500 ml of water, add rice, acute heat and simmer for 5 minutes to open, change Simmer for 20 minutes, as porridge and serve hot.

effect: detoxification.

Indications: early anal fissure, anal swelling, pain, and after the blood of those.

side 3 honeysuckle rice

consists of: honeysuckle 20 grams, 50 grams of rice.

Usage: honeysuckle wash, set the pot, add 500 ml of water, add rice, acute heat and simmer for 5 minutes to open, change Simmer for 20 minutes, into a porridge, hot edible.

effect: detoxification.

Indications: Early anal fissure, see the bright red bleeding after those who have it.

side 4 red bean green bean soup

components: red bean 20 grams of green beans 20 grams.

usage: red bean, mung beans were washed, set the pot, add 500 ml of water, open the emergency heat and simmer 5 minutes, change Simmer for 20 minutes, until the temperature when taking.

effect: detoxification, dampness.

Indications: chronic anal fissure, anal fissure that is more than one year were anal burning.

square 5 kalimeris fried bergamot

composed of: Malan first 50 grams, bergamot 100 grams.

Usage: kalimeris washed, cut into fine, bergamot washed, cut into small pieces heat the pan, fry the kalimeris and bergamot add salt, monosodium glutamate , consumption.

effect: detoxification, blood circulation of qi.

Indications: anal fissure old period, that fissure more than 1 year, patients unhealed for a long time.

side 6 fresh beans drink

composition: 50 g of fresh beans.

Usage: wash fresh beans, set the pot, add 500 ml of water, emergency fire to boil for 5 minutes Simmer for lo minutes, the juice, fractionated consumption.

effects: blood detoxification.

Indications: anal fissure old period.

side 7 honey pickled walnut

composition: 20 grams of honey, walnuts 50 grams.

Usage: walnut wash, drying research into fine, honey, pickled reconcile, graded for human consumption.

effects: blood circulation, laxative.

Indications: anal fissure old period.

side 8 banana milk drink

components: two bananas, milk, 200 grams.

Usage: bananas, peeled, cut into small pieces, heated milk, add banana slices, divided doses.

effects: constipation blood.

Indications: anal fissure old period.

side 9 sugar salted lotus root

components: lotus 250 grams, 50 grams of sugar.

Usage: lotus root, washed, peeled, cut into filaments, sugar pickled for 10 minutes, you can eat.

effects: blood purge.

Indications: anal fissure old period.

mixed with sesame spinach square 10: 1 kg of cooked spinach, sesame paste, 1 two, soy sauce, salt, ginger, msg amount, eat salad. Has a good laxative effect, reduce the defecation anal pain.

side 11 cistanche pork stew: cistanche 200 grams, 500 grams of pork, fennel, pepper, ginger, soy sauce, simmered Dunlan, several times taking. cistanche taste delicious, stew meat, eaten with the same after, for habitual constipation tonic laxative effect, can reduce bowel movements in patients with anal fissure pain.

anal fissure what to eat for good health?

1, anal fissure patients should eat more fiber and vitamin rich fruits, vegetables, prevent constipation.

2, apple, peach, apricot, pears, bananas, melons and other fruits, celery, spinach, leeks, alfalfa, day lily, wild rice, bamboo shoots and other vegetables, are rich cellulose and vitamins should be consumed daily, can make the stool soft and easy to discharge, reduce dry hard fecal stimulation of the anal wound and promote wound healing.

3, sesame seeds, honey, vegetable oil, walnuts can be laxative, anal fissure patients should be more appropriate for human consumption.

4, the role can eat food with blood intestines such as longan, jujube, walnut, flax, fungus, Sang Yan, pine nuts and other

anal fissure better not to eat what food?

anal fissure patients should not eat or Eat spicy food, such as wine, rice wine, pepper, raw ginger, garlic, onions, etc., these diets can lead to constipation, and to the Ministry of congestive obvious anorectal, induce or aggravate anal fissure.

anal fissure how to prevent?

self-examination

how to determine that she has anal

anal fissure is a laceration of skin ulcers formed, with anal pain, bleeding, constipation, anal itching as the main symptoms.

each of the anus is wrong with people first thought is "I will not got hemorrhoids." Many people are so anal fissure bleeding, due to ignorance of the disease, thus increasing doubt and worry, worry people even think that this is a precursor to colon cancer. In fact, anal fissure and hemorrhoids, colon cancer is very obvious difference. according to reports, bleeding hemorrhoids and anal fissure showed a bright red, but each has distinct characteristics, while the former is less pain, bloody toilet paper is usually a maximum of only a few drops; the latter quantity and pain, bleeding usually more than 10 drops. And colorectal cancer patients often dark red bleeding stool, mixed with mucus or pus, and a drastically altered bowel habits, stool frequency increased, accompanied by heavy feeling after the first emergency. If the diarrhea still can not converge after treatment, they should pay special attention. In addition, the three groups are not the same disease, hemorrhoids and anal fissure may occur at any age person, and cancer patients are mostly middle-aged or elderly.

anal fissure patients should not do rectal examination

rectal examination in the diagnosis of many anorectal diseases are very good results, and easy to operate, it is commonly used in medical anorectal examination methods. But nothing is a panacea, rectal is no exception. For example, rectal examination can not be used for anal fissure.

typical symptoms of anal fissure is pain, constipation, bleeding. When dry and hard stool defecation direct squeeze rub ulcers and distraction gap, resulting in severe pain, fecal short-term pain relief, after a few minutes because the sphincter reflex spasm, causing intense pain in a long time, and some required analgesics be alleviated. Therefore, fear of defecation in patients with anal fissure, so that constipation is more severe, creating a vicious cycle.

anal fissure home self method

main clinical manifestations of anal pain, bleeding, constipation, anal itching, etc. symptoms, we can make these symptoms of anal fissure home in self-examination, if you have these symptoms, then go to hospital for treatment it.

① whether the pain: The main manifestations of severe pain, persistent ju Teng, sustainable intensification automatically after a few hours to ease.

② is bleeding: defecation, the damage to the wound, can cause cracks bleeding.

anal fissure treatment considerations?

anal fissure is a disease the more of a pain, and may be associated with a number of anal discomfort, therefore, should focus on prevention of anal fissure.

keep stool, to develop the habit of regular bowel movements a day found that dry stool guitar, avoid efforts to select defecation, and use warm salt water enema or injected into the anal enema laxative.

timely treatment of anal crypt inflammation to prevent infection after the formation of ulcers and subcutaneous fistula.

with anal speculum for examination, should not use the speculum rough handling, damage to the anal canal.

timely treatment of anal fissure caused by a variety of diseases such as ulcerative colitis and other diseases, to prevent the occurrence of anal fissure.

to drink less, do not eating spicy food, not too fine, to match the thickness of grain, vegetables and other foods rich in fiber intake as much as possible, can maintain normal stool.

who have anal weeks of eczema, dermatitis, itching and other diseases to active treatment, prevent hardening of the perianal skin, reduced elasticity and tear anal skin.

to have anal skin lesions, should be active treatment, prevent infection and the formation of ulcers.

inflammation of the anal crypts and anal with papillitis, and they should be cured as soon as possible, to prevent induced anal fissure.

for anal rectal examination, avoid violent force, so as not to damage the anal canal.

anal fissure medicine treatment

medicine for the treatment of anal fissure, not only in surgical technology, many original, but also in drug treatment has a very extensive medical experience.

(1) Zaohuo will end: General Zheng Jian dry hard stool knot, defecation anal pain, and after a slight relief, sustainable pain a few hours later, and even then the pain is not all day cut, then when the blood along with the next, mostly guttate. often painful due to dry guitar stool, and dare not eat normally, accompanied by upset, mouth and throat, dry yellow tongue coating, rapid pulse.

Card is: Zaohuo knot, knot in the gut.

Governing law: should be heat and purging fire, laxative

side with: golden gardenia pills, or as a side addition and subtraction using external use Qudu soup Fumigation, apply paste to the wound granulation Yuhong.

(2) heat Accumulation: abdominal pain and discomfort when they, defecation unhappy, anal, when mucus blood, or with pus, thick yellow greasy moss.

Card is: damp, accumulation in the anus.

Governing Law: Thanh Hoa heat, laxative.

side with: coptis decoction Oral.

apply topical ointment anal fissure at the four yellow. or back to the anal scattered

(3) deficiency of intestinal dryness: it anal pain, bleeding, constipation, dry skin, dry mouth, insomnia, hot flashes afternoon, red tongue, little coating, pulse breakdown.

Card is: dry intestinal blood deficiency, end of the fire.

Governing Law: cooling support blood, moistening purge.

side with: maren Runchang pills, or fried with Jichuan can.

western anal fissure treatment

(a) treatment

principle is to soften the stool to maintain smooth stool, stop pain, relieve sphincter spasm, break the vicious cycle, to promote wound healing. Specific measures are as follows:

1. keep stool oral laxatives, the stool soft , lubrication, increased multi-fiber food intake and change in bowel habits, and gradually correct the occurrence of constipation.

2. defecation before and after local bath temperature with 1:5000 potassium permanganate solution bath to keep the local clean.

3. anal dilator for acute or chronic anal fissure is not concurrent papillary hypertrophy and sentinel hemorrhoids. the advantage of easy operation, no special equipment, rapid effect, just a day after bath you can.

methods: local anesthesia, the patient in lateral position, the first expansion to 2 index finger forced anal tube, and then gradually inserted into the two middle fingers, to maintain the expansion 5min (Figure 5) around the direction of the expansion in the male should avoid finger contact with the impact of expansion of the ischial tuberosity, female pelvic width, there is no problem. anal canal expansion, to go In addition to the anal sphincter spasm, pain immediately after it. expansion, anal fissure wound to expand and open, unobstructed drainage, superficial wound healed quickly, but this method is complicated by the lack of bleeding, perianal abscesses, hemorrhoids off vertical and short-term fecal incontinence, and the higher recurrence rate.

4. Topical application of nitroglycerin ointment Lund et al (1997) reported a 0.2% nitroglycerin ointment applied to the anal crack at, 2 times / d, a total of 4 to 6 weeks. The results showed that treatment 20min after maximum resting anal canal pressure decreased from 122.1 ± 44cmH2O 72.5cmH2O, the equivalent of one-off "chemical sphincterotomy." treatment of 39 cases of chronic anal crack, 33 patients were cured, 14 cases cured in four weeks; defecation pain disappeared within 2 weeks; recurrence in 5 cases, 4 cases were cured after treatment again; no 1 case of incontinence, but treatment in 8 patients mild pain. Law is the treatment of chronic anal fissure is a better non-surgical methods, but still the bulk of cases and long-term follow-up randomized controlled study.

5. meat Local injection of botulinum toxin poisoning toxins in small doses have weakened the role of internal sphincter. Jost with the drug treatment of 12 patients with chronic anal fissure, anal fissure near the external sphincter injection 0.1ml by dilution of botulinum toxin (50U/ml). 8 Example 1 day after the injection pain will disappear, 5 days squeezing pressure measurement shows the maximum pressure drop at random, 3 月 10 cases of wound healing after treatment in 50 cases, 3 cases of incontinence, and 5 female patients developed anal weeks of thrombosis, no such complications men. efficacy of this method remains to be further summarized.

6. surgical therapy for prolonged healing, non-surgical treatment of chronic anal fissure invalid can be used following surgery.

(1) anal fissure surgery: the removal of the triangular-shaped fissure and the surrounding skin, under local anesthesia or spinal anesthesia to take the spindle or fan-shaped incision, total removal of the sentinel hemorrhoids, hypertrophic anal papillae, anal fissure, if necessary, the vertical cut off part of the sphincter (Figure 6) of the Act advantage is total removal of lesion, wound wide, unobstructed drainage, facilitate the growth of granulation tissue from the base, but its drawback is that leaving a large wound, wound healing is slow.

(2) internal sphincterotomy: a gastrointestinal involuntary internal sphincter muscle of circular features, easy to spasm and contraction, which is the main reason for the pain caused by anal fissure, it can be used sphincterotomy treatment of anal fissure. the general part of the internal sphincterotomy rarely cause incontinence. method has the following three kinds.

① posterior internal sphincterotomy: lithotomy position or prone position, under local anesthesia or general anesthesia, leaves open double anal fissure after the middle of the mirror display, directly through the fissure cut off the lower edge of the internal sphincter from the anal verge to the dentate line, about 1.5cm, internal and external sphincter should be separation between the organization and sometimes cut the lower sphincter to facilitate drainage (Figure 7). if inflammation anal sinus, hypertrophy of the nipple or external hemorrhoids, which can be removed. the wound open to heal, but this method is slow wound healing, sometimes "lock holes" deformity, affecting the anal function of the elderly anal relaxation are combined rectal prolapse and anal dysfunction, this procedure should not be lines.

② open lateral internal sphincterotomy: touch the sphincter between the ditch, the outer edge of the skin do the anal curved 2cm incision, using curved forceps out into the sphincter between the ditch by the incision, revealing the internal sphincter, the use of two curved vascular clamp to live under the edge of the sphincter to the dentate line on the isolated, under direct vision with scissors to cut off part of the internal sphincter sent to biopsy, to confirm whether the sphincter, the two ends hung ligation or bleeding, skin with silk suture (Figure 8) of the Act advantages: surgery under direct vision, muscle completely cut off, bleeding completely, and to take tissue biopsy.

③ lateral subcutaneous sphincterotomy: local anesthesia, touch the sphincter between the ditch, with eye cataract knife piercing into the internal and external sphincter, between the outward within the internal sphincterotomy (Figure 9), to avoid penetrating anal skin of the Act advantages: avoiding open wounds, relieve pain. wound healing. Disadvantages: cut muscle, not completely, and sometimes easy bleeding, so The surgery is only suitable for experienced doctors. Marti (1994) advocated the lateral subcutaneous internal sphincterotomy will be B-spin probe into the rectum within the anal canal, immediately after the cut muscle B-rotating probe inspection of the internal sphincter is have been cut off, and can identify its scope, this probe can avoid surgery by finger into the rectum, but contribute to the surgical procedure. resection of the above two methods can be both external hemorrhoids and hypertrophic nipple.

(3) flap surgery: for skin defects and anal fissure was narrow, ie, the line parallel flap after resection of anal fissure surgery.

7. Laser therapy is mainly used for the treatment of chronic anal fissure. First Hospital of beijing Medical University reported using C02 laser ablation of anal fissure lesions and full-thickness internal sphincter. 208 cases of anal fissure cure 1 204 (98.1%), recurrence in 4 cases (1.9%), including three cases of recovery after laser surgery again, and 1 switch surgery outside the hospital, the average healing time of 4 weeks (2 to 6 weeks). C02 laser treatment of chronic anal fissure has the following advantages: ① laser have the dual effect of cutting and coagulation, so cutting and bleeding quickly. ② analgesic effect: laser lymphatic vessels and nerve endings exposed the role of coagulation, reducing postoperative edema and inhibited the release of neurotransmitters, the Ministry of wound pain or pain to reduce. ③ anti-infection ability: high-temperature laser can kill bacteria, the cutting part of the formation of carbon, coagulation, cell infiltration layer, can prevent the invasion of bacteria, so patients may need antibiotics. ④ small scar, fast healing. ⑤ concurrent less disease, most patients do not have analgesic, and without fear for fecal incontinence. The downside is that laser cutting and coagulation to stop bleeding in small amounts of smoke, the operating room should have good ventilation and exhaust devices.

anal fissure diet Methods: lotus 500 grams of silkworm 7, brown sugar, 120 grams, washed cut into thick slices lotus root, and the silkworm, brown sugar wok of boiling water, eating lotus root soup, day 1 for 7 days. This side of the anal fissure have a certain effect.

therapeutic side only as an adjunct treatment, efficacy varies in case of anal fissure attack, be sure to go to regular hospitals for diagnosis and treatment, to a speedy recovery.

(b) the prognosis

currently no related content description.

anal fissure which checks should be done?

addition to the anus outside the general visual examination without special inspection, but if the cause is unknown or associated with other diseases, as the case use the appropriate inspection program.

1. digital rectal examination and endoscopy can be difficult to diagnosis of anal fissure, where appropriate, digital rectal examination and anoscopy, the operation should be gentle movements, so as not to cause the patient play pain.

2. histopathology of chronic ulcers in the lateral view, to think about whether tuberculosis, cancer, crohn's disease and ulcerative colitis and other rare diseases, the line biopsy may be the differential diagnosis.

anal diseases easily confused?

be with tuberculous ulcers, syphilis, ulcers, chancroid ulcers and differentiated epithelial cancer. Including ulcerative colitis and granulomatous colitis complicated by the fissure can easily identify.

1. anal fissure skin abrasions and anal skin abrasions early to be differentiated (Table 2).

2. inflammatory bowel disease may be associated with certain inflammatory bowel diseases, ulcers around the anus, should pay attention to differential diagnosis. ① anal tuberculosis ulcers; ② Crohn's disease, anal ulcer; ③ syphilis ulcers; ④ ulcerative colitis complicated by the anal fissure.

anal fissure may be caused by the diseases?

fissure-related diseases

between sigmoid hernia

more hip symptoms

vaginal discharge will be diluted when the blood was bright red blood in the stool incontinence guttate persistent pain at the sacrum sacral dysplasia with green manure odor fecal impaction have fecal check, see brown eggs or feces to see red itchy groin anal reflex anal sphincter narrow transverse fissure anal fissure anal polyp anal fissure triad of anal ulcer disease