Anal Fissures and Fistulas

At Mayo Clinic Healthcare in central London, our Gastroenterology specialists work collaboratively to diagnose and treat anal fissures and anal fistulas with precision and discretion.

Using advanced diagnostic investigations and a multidisciplinary approach, we aim to identify the underlying cause of your symptoms and develop a personalised treatment plan tailored to your individual needs.

Anal fissures and anal fistulas are conditions that affect the anal canal and surrounding tissues. Although the symptoms can sometimes overlap, they are distinct conditions requiring different forms of treatment.

An anal fissure is a small tear in the lining of the anal canal, often caused by trauma during bowel movements. Fissures can cause significant discomfort, particularly during and after passing stools.

An anal fistula, also known as a perianal fistula, is an abnormal tunnel that develops between the anal canal and the skin surrounding the anus. Most fistulas develop following an infection or anal abscess and may lead to persistent pain, swelling and discharge.

Early assessment is important to relieve symptoms, prevent complications and determine the most appropriate treatment approach.
The symptoms of anal fissures and anal fistulas can be similar in some cases. Our specialists perform a detailed assessment to establish the underlying cause of your symptoms. Symptoms may include:

Anal Fissures:

Intense burning pain during and after bowel movements

Bright red blood on the stool or toilet paper

Skin tag near fissure (sometimes)

Anal Fistulas:

Persistent pain (often throbbing)

Skin irritation

Pus discharge near the anus

Fever (sometimes)

You should seek medical advice if symptoms persist, worsen, or interfere with your daily quality of life.
Anal fissures and fistulas develop for different reasons. However, in some cases, a fissure may become infected and lead to a fistula. The causes of both conditions are as follows:

Causes of Anal Fissures:

Constipation and Straining (passing large/dry stools)

Chronic diarrhoea (frequent loose bowel movements irritate the anal lining)

Childbirth-related trauma (this can tear the lining)

Increased tension in the anal sphincter muscles

Causes of Anal Fistulas:

Previous anal abscess

Crohn's disease

Diverticulitis

Hidradenitis Suppurativa

Tuberculosis- or HIV related infection

A complication of surgery

In some patients, additional gastrointestinal investigations may be required to identify underlying inflammatory bowel disease or other contributing conditions.
At Mayo Clinic Healthcare, diagnosis begins with a detailed consultation and clinical assessment. Your specialist will discuss your symptoms, medical history and any relevant family history before performing a gentle examination of the affected area.

Anal fissures are often visible during examination. Anal fistulas can be more complex and may require additional imaging to assess the location and extent of the tract.

Investigations for anal fissures include:

Anoscopy, using a small illuminated instrument to examine the anal canal

Flexible sigmoidoscopy to assess the lower bowel

Colonoscopy where further evaluation is required, particularly if there is rectal bleeding or concern regarding inflammatory bowel disease

The process of diagnosing anal fistulas is more complex than anal fissures, as the condition involves abnormal tracts within the anal canal and surrounding tissues

Investigations for anal fistulas include:

Physical examination to identify swelling or drainage

Digital rectal examination

Anoscopy

MRI scanning to map the fistula tract and surrounding tissues

Endoanal ultrasound to assess sphincter muscles and detect abnormalities

Where appropriate, your care may involve collaboration between gastroenterologists, colorectal specialists and radiologists to ensure an accurate diagnosis and carefully coordinated treatment plan.
Treatment will depend on whether you are diagnosed with anal fissures or anal fistulas.

Anal fissure treatment

Anal fissure treatment focuses on relieving pain, softening stools and healing the tear.

Many anal fissures improve with non-surgical treatment. Recommendations may include:

Increasing dietary fibre intake

Improving hydration to soften stools

Warm baths following bowel movements

Topical anaesthetic or anti-inflammatory creams

Glyceryl trinitrate (GTN) ointment

Calcium channel blocker creams

Botox injections where conservative treatment have not been successful

In persistent or chronic cases, surgical anal fissure treatment may occasionally be recommended.

Anal fistula treatment

Treatment for anal fistulas often requires a procedural or surgical approach. Depending on the complexity and cause of the anal fistula, options may include:

Drainage of infection or abscesses

Seton placement

Fistulotomy

Advanced sphincter-preserving procedures

Your consultant will discuss the most appropriate treatment options with you, taking into consideration symptom severity, fistula complexity and long-term bowel function. For surgical approaches, your consultant will refer you to a partnering clinic specialising in surgery.

Your Mayo Clinic specialist will create a personalised treatment plan tailored to manage your symptoms, minimise your risk of further discomfort, and support your long-term health and well-being.
Mayo Clinic Healthcare combines internationally recognised expertise with highly personalised care in the heart of central London.

Patients benefit from:

Access to world-class gastroenterology and colorectal specialists

A multidisciplinary approach to complex anorectal conditions

Advanced diagnostic imaging and investigations

Evidence-based treatment informed by Mayo Clinic’s global medical expertise

Dedicated support for UK-based and international patients

Our consultants work closely together to ensure every patient receives coordinated, compassionate and expert-led care throughout their treatment journey.

Private health insurance

Mayo Clinic Healthcare works with all major private health insurance providers, including AXA Health, Aviva, BUPA, Health Partners Group, Vitality Health and WPA. Self-pay arrangements are also available.

Private assessment for anal fissures and fistulas

If you’re experiencing any of the symptoms of anal fissures or fistulas, our consultants in central London can help. To request an appointment, you can fill out the online enquiry form or contact us on tel: +44 (0) 207 871 2575.

Medically Reviewed by

Dr Sarmed Sami, Consultant Gastroenterologist