Anal fissure is a small linear tear in the lining of the anal canal. It commonly causes sharp, tearing pain during a bowel movement, pain that continues afterwards, and a small amount of bright-red blood on toilet tissue. Constipation and hard stool are frequent triggers, but repeated diarrhoea and other conditions can also injure the anal lining. These notes explain how nurses assess the condition, support comfort and bowel health, recognize warning signs, and contribute to safe treatment.

Clinical safety: Rectal bleeding and anal pain need an appropriate assessment. Do not assume they are caused by a fissure or haemorrhoids. Severe or increasing pain, fever, pus, heavy bleeding, dizziness, a new mass, or an atypical or non-healing lesion requires prompt clinician review. This lesson is for nursing education and does not replace examination, prescribing guidance, or local referral protocols.

By the end of this lesson, the learner should be able to:

• Define an anal fissure and distinguish acute from chronic disease.
• Explain common causes, symptoms, and the pain–spasm cycle that can delay healing.
• Describe a respectful, focused nursing assessment and identify atypical presentations and red flags.
• Outline conservative, topical, specialist, and surgical treatment options without prescribing for an individual patient.
• Plan nursing care, patient education, follow-up, and referral.

A fissure is a superficial or deeper linear split in the anoderm, the sensitive skin-like lining of the anal canal. A typical fissure begins near the dentate line and extends toward the anal verge. The anal canal is controlled by the internal anal sphincter, which is involuntary, and the external sphincter, which is under voluntary control. The internal sphincter normally maintains resting tone. Persistent spasm or raised resting pressure can reduce local blood flow and make a tear slower to heal.

Fissures are often described by duration and appearance. Acute fissures are recent tears without established chronic changes. Chronic fissures persist and may develop characteristic features such as a sentinel skin tag at the outer edge, a hypertrophied anal papilla inside the canal, thickened edges, or visible sphincter fibres at the base. Definitions of duration vary between references; symptoms lasting several weeks, recurring, or showing chronic features should prompt clinical review rather than prolonged self-treatment.

Most primary fissures follow mechanical injury to the anal lining. A large or hard stool can stretch and tear the anoderm. Frequent loose stool and straining may produce repeated irritation. Pain then causes involuntary internal sphincter spasm; spasm may further reduce blood supply and make defecation more painful. The person may delay opening the bowels, stools become harder, and the cycle continues.

• Constipation, hard stool, or infrequent bowel movements.
• Repeated diarrhoea or frequent bowel motions.
• Straining, prolonged sitting on the toilet, or suppressing the urge to defecate.
• Childbirth or local trauma; a careful history is important and should be obtained respectfully.
• Inflammatory bowel disease, especially Crohn disease, or other causes of chronic inflammation.
• Less commonly, infections, immunosuppression, tuberculosis, sexually transmitted infections, or malignancy can cause secondary or atypical fissures.

• Sharp pain with defecation: often described as cutting, tearing, or like passing glass.
• Pain after the bowel movement: may persist for minutes or hours and can lead to fear of defecation.
• Small-volume bright-red bleeding: usually noticed on tissue or the surface of stool; bleeding may be absent.
• Constipation or stool withholding: may develop because of pain, even when constipation was not the original trigger.
• Local irritation or a skin tag: can occur, particularly with chronic fissure.

Systemic illness is not expected with an uncomplicated fissure. Fever, chills, purulent discharge, spreading redness, a fluctuant swelling, severe constant throbbing pain, or feeling unwell suggests another or additional problem such as an abscess and requires urgent assessment.

A single posterior or anterior midline tear is the usual pattern. Lateral fissures, multiple fissures, painless ulcers, an irregular mass, or lesions that fail to heal need a broader assessment. Possible secondary causes include Crohn disease, HIV-related disease, syphilis and other sexually transmitted infections, tuberculosis, haematological disease, trauma, and anal or colorectal malignancy. Testing should be guided by the history, examination, and clinician judgment.

Remember: A typical fissure often produces severe pain even when visible bleeding is only a few spots. Conversely, painless or persistent bleeding still requires assessment for other causes.

• Ask when pain began, where it is felt, its severity, whether it starts with defecation, and how long it lasts afterwards.
• Clarify the amount, colour, and pattern of bleeding; ask about blood mixed through stool, clots, or bleeding between bowel movements.
• Review bowel frequency, stool consistency, straining, urgency, diarrhoea, fluid and food patterns, and use of laxatives.
• Ask about fever, swelling, discharge, abdominal pain, weight loss, appetite change, fatigue, and recent change in bowel habit.
• Review pregnancy or recent childbirth, previous anorectal problems or surgery, continence, inflammatory bowel disease, immune status, relevant infections, current medicines, and allergies.
• Explore the effect on eating, sleep, work, mobility, hygiene, and willingness to open the bowels. Use neutral language and protect privacy.

1. Explain the examination, obtain informed consent, offer a chaperone according to policy, and use privacy, good lighting, gloves, and a respectful approach.
2. Inspect the perianal area gently for a visible midline tear, skin tag, swelling, redness, discharge, prolapse, scars, or atypical lesions. Avoid unnecessary manipulation.
3. A digital rectal examination or anoscopy may be too painful in an acute fissure. The clinician may defer these until pain is controlled or arrange examination under anaesthesia if necessary. Never force an examination.
4. Diagnosis is often clinical. Further tests are considered when bleeding is unexplained, the lesion is atypical or non-healing, symptoms suggest inflammatory or infectious disease, or age and risk factors indicate assessment of the colon.

Document the patient’s own description of symptoms, the site and appearance observed, bleeding pattern, pain score, bowel history, consent and chaperone, actions taken, referrals, and response to care. Record negative findings that help show why an urgent complication was considered less likely.

• Heavy or ongoing bleeding, clots, fainting, dizziness, pallor, or signs of haemodynamic compromise.
• Fever, rigors, purulent discharge, spreading redness, or a tender fluctuant swelling.
• Severe constant or rapidly worsening pain, urinary difficulty, or systemic illness.
• A lateral, multiple, irregular, ulcerated, or mass-like lesion.
• Persistent or recurrent bleeding, unexplained weight loss, anaemia, new change in bowel habit, abdominal mass, or relevant family history of colorectal cancer.
• Failure to improve, recurrence, or persistent symptoms despite an appropriate treatment plan.

Escalate according to the patient’s acuity and local pathway. Emergency features require urgent assessment; atypical or persistent features need timely clinician or colorectal review. Follow local protocols for referral and investigations.

Management aims to reduce repeated injury, relieve pain, support healing, and investigate secondary causes. Treatment depends on duration, examination findings, patient history, medicines, pregnancy or breastfeeding status, continence risk, and local availability. Medication and procedural decisions belong to a qualified prescriber or specialist.

For a recent uncomplicated fissure, conservative measures are commonly tried first. They are also useful alongside prescribed treatment for chronic disease.

• Increase fibre gradually: use fibre-rich foods or a suitable supplement when appropriate. A sudden large increase can cause bloating; titrate to tolerance.
• Maintain appropriate fluids: encourage regular fluids unless the patient has a restriction for cardiac, renal, or another medical condition.
• Keep stools soft and regular: encourage responding to the urge, avoiding prolonged straining, and using a comfortable toilet position. A clinician may recommend a stool softener or osmotic laxative when needed.
• Warm sitz baths: sitting in comfortably warm water after a bowel movement may ease discomfort and help the person relax. Avoid hot water that can burn skin.
• Pain relief: use analgesia only according to the prescribed plan, allergies, comorbidities, and local guidance. A topical local anaesthetic may be prescribed for short-term symptom relief; prolonged or unsupervised use can irritate skin or mask worsening symptoms.
• Gentle hygiene: clean with water or a soft unscented material and pat dry. Avoid vigorous wiping and irritating perfumed products.

Explain that complete healing may take time and arrange follow-up. If pain or bleeding persists, reassessment is important rather than indefinitely repeating self-care.

For persistent or chronic fissures, clinicians may prescribe topical medicines that reduce internal sphincter tone and improve local blood flow. Options include topical glyceryl trinitrate (nitroglycerin) or topical calcium-channel blockers such as diltiazem or nifedipine, depending on local guidance and availability. The exact preparation and duration must follow the prescriber and local formulary; do not copy a dose from another patient or website.

• Topical nitrate: can help healing but commonly causes headache and may cause dizziness or low blood pressure. It can interact with phosphodiesterase-5 medicines and other drugs that lower blood pressure; screen and refer questions to the prescriber or pharmacist.
• Topical calcium-channel blocker: may be used as an alternative and is often better tolerated than nitrate therapy. Topical treatment is generally preferred to oral use for this purpose because it limits systemic adverse effects.
• Medication counselling: explain how and when the prescribed product is to be used, hand hygiene, expected effects, possible side effects, interactions to disclose, and when to stop and seek advice. Do not apply a product internally unless its instructions specifically say to do so.

Injection of botulinum toxin into the internal sphincter may be considered by a trained clinician when a fissure does not respond to initial treatment or when another option is unsuitable. It temporarily reduces muscle spasm. The choice, injection technique, and follow-up are specialist decisions; recurrence and temporary continence problems are possible.

Selected chronic fissures that persist despite non-operative treatment may be treated surgically. Lateral internal sphincterotomy (LIS) is effective for appropriately selected patients, but it can impair continence. Before surgery, the specialist considers previous faecal incontinence, obstetric sphincter injury, inflammatory bowel disease, prior anorectal operations, and any known sphincter damage. A tailored sphincterotomy or sphincter-preserving advancement flap may be considered when continence risk is higher. Routine manual anal dilation is generally avoided because of the risk of sphincter injury and incontinence.

Nursing responsibilities include preparation according to local pre-operative policy, confirming the consent and plan are documented by the responsible clinician, medication and allergy checks, privacy, emotional support, and post-operative monitoring of pain, bleeding, wound or discharge, urinary retention, bowel function, and continence. Reinforce stool-softening instructions and follow-up before discharge.

Individual care depends on the patient’s symptoms, examination findings and clinician’s plan. Apply prescribed treatments only and follow the facility protocol.

• Explain in simple terms what a fissure is and why pain can continue after a bowel movement.
• Encourage gradual fibre intake, appropriate fluids, regular activity, and avoiding straining or delaying defecation.
• Explain how to use any prescribed topical medicine and what side effects need a call to the clinician. Do not share medicines.
• Advise review for ongoing or recurrent bleeding, increasing pain, fever, pus, a lump, dizziness, or a change in bowel habits.
• Normalize the discussion: anorectal symptoms are common, and asking for help early can prevent prolonged pain and identify other causes.

Many acute fissures improve with conservative treatment. Persistent fissures may become chronic and cause repeated pain, bleeding, distress, and avoidance of bowel movements. Secondary constipation can worsen the tear. Untreated infection is not a usual complication of a simple fissure; fever, pus, or swelling should lead the nurse to consider a co-existing abscess or another diagnosis. Surgical treatment can be effective but carries a continence risk, which is why careful selection and counselling matter.

Case: A 29-year-old adult reports severe sharp pain during bowel movements and a small streak of bright-red blood on tissue for five days. They have been passing hard stool and now delay going to the toilet. They are afebrile and do not report discharge or abdominal symptoms.

1. Most likely working diagnosis? A typical acute anal fissure is possible, but a clinician must assess the symptoms and exclude other causes.
2. What should the nurse assess? Pain and bleeding pattern, stool consistency and frequency, straining, relevant history, medicines, allergies, red flags, and effect on daily life.
3. What care can be discussed? Gentle hygiene, warm sitz baths, gradual fibre, appropriate fluids, avoiding straining, prescribed pain relief or stool regulation, and timely follow-up.
4. Which findings require escalation? Fever, pus, swelling, heavy bleeding, dizziness, a lateral or multiple lesion, persistent bleeding, weight loss, or worsening symptoms.

No. Constipation and hard stool are common triggers, but diarrhoea and other forms of trauma or secondary disease can also cause fissures.

No. A fissure can cause bright-red bleeding, but bleeding also occurs with other conditions. Persistent, recurrent, heavy, or unexplained bleeding needs clinical assessment.

A digital rectal examination or anoscopy can be very painful during an acute fissure. The clinician may inspect gently and defer more invasive examination until pain is controlled or plan another setting if needed.

Specialist treatment is considered for selected persistent or chronic fissures when non-operative care has not worked or is unsuitable. The benefits and risks, especially possible continence change, must be discussed individually.

• A fissure is a tear in the anal lining; severe pain with defecation and small bright-red bleeding are common.
• Constipation, hard stool, and diarrhoea can cause repeated trauma; pain-related sphincter spasm can delay healing.
• Posterior and anterior midline fissures are typical. Lateral, multiple, irregular, or non-healing lesions require a search for secondary causes.
• Early care commonly focuses on stool regulation, warm baths, comfort, and follow-up; persistent disease may need prescribed topical or specialist treatment.
• Assess red flags, do not force painful examinations, protect privacy, and do not attribute all rectal bleeding to a fissure.

1. Davids JS, Hawkins AT, Bhama AR, et al. The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Anal Fissures. Diseases of the Colon & Rectum. 2023;66(2):190–199. doi:10.1097/DCR.0000000000002664. Read the ASCRS guideline.
2. Ministry of Health, Uganda. Uganda Clinical Guidelines 2023: National Guidelines for Management of Common Health Conditions. Section 6.4.2, Haemorrhoids (Piles) and Anal Fissures. Uganda Ministry of Health guideline portal.

These notes support nursing revision and should be used alongside supervised clinical practice and current local protocols.

Related nursing notes

Continue with the other Anal rectal conditions in the Diploma in Nursing Direct Curriculum, or review Hemorrhoids (Piles): Symptoms, Treatment and Nursing Care.