Anal fissures are small tears or cracks in the lining of the anus. They cause pain and bleeding during bowel movements, affecting people of all ages. In India, where diet and lifestyle factors vary widely, anal fissures are a common complaint in clinics.

Understanding the difference between acute and chronic fissures is important for effective treatment.

This article explains the main differences between acute and chronic anal fissures, the symptoms, when to seek treatment, and how doctors decide on the best treatment approach or threshold. We aim to provide clear, practical information relevant to the Indian population.

What are Anal Fissures?

A fissure is a small tear in the skin around the anus. It happens when hard stools, constipation, or frequent diarrhoea cause excessive strain during bowel movements. This tear affects the sensitive anal mucosa, causing sharp pain and sometimes bleeding.

The fissure may heal within a few weeks with simple treatment or may persist and become chronic. The key to managing fissures is identifying whether they are acute or chronic.

Acute vs Chronic Fissure: Definition and Differences

  • Acute fissure refers to a fresh tear in the anal skin. It usually appears suddenly due to strain during defecation or injury. The symptoms are sharp pain and sometimes mild bleeding during stool passage. The acute fissure is thin, superficial, and usually heals in a few weeks with conservative care.
  • A chronic fissure lasts for more than 6 weeks. It involves deeper tissue damage. The edges of the fissure become thickened and hardened (called fibrotic). There may be a visible skin tag or sentinel pile at the edge of the tear. Chronic fissures often fail to heal on their own due to continued spasm of the internal anal sphincter muscle, decreased blood flow, and fibrosis.

Symptoms of Acute vs Chronic Fissures

Both types share common symptoms but differ in severity and duration:

  • Acute fissure symptoms:
    • Sharp, severe pain during and shortly after bowel movements
    • Bright red bleeding on toilet tissue or stool
    • Spasm of the anal muscles causes difficulty in passing stool.
    • Mild swelling or redness around the anus
  • Chronic fissure symptoms:
    • Persistent, dull, or burning pain even after defecation
    • Occasional or continuous bleeding
    • Presence of skin tags or lumps near the fissure
    • Anal itching or irritation
    • Constipation due to fear of pain

Causes and Risk Factors

Both acute and chronic fissures result from similar causes:

  • Passing hard, dry stool or straining
  • Chronic constipation or diarrhoea
  • Childbirth or anal trauma
  • Inflammatory bowel disease (Crohn’s disease)
  • Poor blood supply to the anal area
  • Frequent anal sex

In India, diets low in fibre, low water intake, and a sedentary lifestyle increase the risk of fissure development.

Diagnosis

Doctors diagnose fissures by clinical examination. Usually, the patient’s history and physical inspection are enough to identify the fissure.

  • Acute fissures appear as a fresh, shallow cut.
  • Chronic fissures show hardened edges, skin tags, or sentinel piles.
  • In some cases, an anoscopy or proctoscopy may be done to look inside the anal canal and rule out other conditions such as infections, Crohn’s disease, or cancer.

Treatment Overview: Acute vs Chronic Fissure

The goal of fissure treatment is to relieve pain, promote healing, reduce sphincter spasm, and prevent recurrence.

However, treatment thresholds differ according to whether the fissure is acute or chronic.

Treatment Threshold for Acute Fissures

Acute fissures usually respond well to simple medical management. Non-surgical treatment will be the first choice, and invasive procedures are rarely needed.

  • Diet and Lifestyle Modification:
  • Increasing fibre intake (such as dals, vegetables, and fruits) and drinking at least 2-3 litres of water daily will help soften stool. Patients should avoid straining and maintain a regular bowel routine.
  • Sitz Baths:
  • Warm water baths 2-3 times daily reduce anal sphincter spasm and relieve pain.
  • Topical Medications:
  • Creams containing local anaesthetics (lidocaine) help reduce pain. Nitroglycerin ointment or diltiazem cream relaxes the sphincter muscle, promoting healing.
  • Stool Softeners:
  • Medicines like lactulose or polyethylene glycol soften stools and ease defecation.
  • Pain Control:
  • Simple analgesics such as paracetamol or ibuprofen reduce pain as needed.

Most acute fissures heal within 4-6 weeks with these measures.

Treatment Threshold for Chronic Fissures

Chronic fissures require more aggressive treatment because conservative measures often fail.

  • Extended Medical Therapy:
  • Use of topical nitrates, calcium channel blockers, or botulinum toxin injection may reduce sphincter spasm over several weeks. These treatments have variable success but avoid surgery.
  • Surgical Intervention:
  • Surgery is usually recommended when:
    • Fissure pain continues beyond 6-8 weeks despite medical treatment.
    • There is a large sentinel pile or skin tag.
    • The fissure is recurrent or very deep.
    • The patient develops complications such as anal stenosis or abscess.

The most common surgery is lateral internal sphincterotomy. This procedure cuts a small portion of the internal anal sphincter muscle to reduce spasm and improve blood flow. The success rate is high, and healing happens faster with less pain.

Other surgical options include fissure excision and advancement flap procedures in complicated cases.

When to Refer to a Specialist?

Patients must see a doctor immediately if fissure symptoms include:

  • Severe bleeding or bleeding beyond a few days
  • Signs of infection or abscess: swelling, fever, pus discharge
  • Severe pain not relieved by medication
  • Anal lumps or persistent itching
  • Associated symptoms such as weight loss, blood mixed with stool, or a change in bowel habits

These can indicate other serious conditions like infections, tuberculosis, or cancer, which need specialist care.

Prevention of Fissures

Preventing fissures is better than treating them. The following steps reduce the risk:

  • Keep stools soft with a high-fibre diet and adequate fluids
  • Avoid straining and prolonged sitting on the toilet
  • Treat constipation promptly
  • Maintain good anal hygiene
  • Exercise regularly to improve bowel function

Conclusion

Understanding the difference between acute and chronic fissures helps set proper treatment goals and thresholds. Acute fissures usually heal well with lifestyle changes and topical medicines within 4-6 weeks. Chronic fissures often require more prolonged treatment, with surgery needed when conservative options fail.

In India, varying diet and lifestyle factors contribute to fissure incidence. Timely diagnosis and treatment will reduce suffering and complications.