An anal fissure is a small tear in the lining of the anal canal, but the discomfort it causes can be significant. Because the area contains many nerve endings and is closely controlled by the internal anal sphincter, even a relatively small tear may cause sharp pain, burning and bleeding during or after bowel movements.
Anal fissures can be acute or chronic. Acute fissures may heal within a few weeks with appropriate conservative treatment, while chronic fissures can persist for more than six to eight weeks or repeatedly return despite initial treatment. When symptoms continue, assessment by a colorectal specialist can help determine the underlying cause and the most appropriate treatment pathway.
What Causes an Anal Fissure?
Anal fissures commonly develop when the anal lining is stretched or irritated beyond its ability to tolerate the mechanical stress. Passing large, hard or dry stools is one of the most frequent causes. Straining during bowel movements can further increase pressure on the tissue.
Repeated diarrhoea can also contribute. Frequent loose stools may irritate the anal lining and prevent the area from recovering between bowel movements.
Other contributing factors can include low dietary fibre intake, inadequate hydration, irregular bowel habits and repeatedly delaying the urge to pass stool. Less common causes include inflammatory bowel conditions such as Crohn’s disease, local infections and reduced blood supply to the area.
Recognising the Symptoms
The symptoms of an anal fissure can be distinctive, although they may overlap with other anorectal conditions such as haemorrhoids.
Common symptoms include:
- Sharp or cutting pain during bowel movements
- Pain that continues for minutes or hours afterwards
- Bright red blood on toilet paper or on the surface of the stool
- Burning or stinging around the anus
- A visible tear or small skin tag near the anal opening
The internal sphincter can go into spasm after a bowel movement. This can prolong pain and reduce blood flow to the affected tissue, creating a cycle in which pain, muscle spasm and delayed healing reinforce one another.
Because anal bleeding can have different causes, persistent or unexplained bleeding should be assessed rather than automatically attributed to a fissure.
How Is an Anal Fissure Diagnosed?
Diagnosis usually begins with a detailed medical history and examination. A colorectal specialist may ask about the duration of symptoms, bowel habits, stool consistency and whether constipation or diarrhoea has been present.
In many cases, a visual inspection of the anal area is sufficient to identify the fissure. A further examination may be considered when necessary, particularly when symptoms could be associated with another anorectal condition.
For unusual or persistent symptoms, or where there is a relevant personal or family history of bowel disease, additional investigations such as colonoscopy may be recommended. This helps ensure that symptoms such as bleeding are properly evaluated rather than assumed to be caused by a fissure.
Non-Surgical Treatment for Anal Fissures
Surgery is not normally the first treatment for an acute anal fissure. Management often begins with measures designed to make bowel movements softer and reduce strain.
Increasing dietary fibre through vegetables, fruits, legumes and whole grains can help produce stools that are easier to pass. Adequate fluid intake is also important. Warm sitz baths for around 10 to 15 minutes after bowel movements may help relax the anal sphincter and provide relief.
When lifestyle measures are insufficient, prescription topical medications such as glyceryl trinitrate (GTN) or diltiazem may be used under medical supervision. Stool softeners or laxatives can also be prescribed when constipation is contributing to the problem.
For some chronic fissures, injection-based treatment such as botulinum toxin may be considered. Botox temporarily relaxes the anal muscle and may give the fissure an opportunity to heal. According to the clinic’s information, its effect generally lasts around three to four months and it may be less effective than surgery, with recurrence possible after the effect wears off.
When Is Surgery Considered?
Surgery may become appropriate when conservative treatment has not successfully resolved the fissure. Factors that may lead a specialist to consider surgery include a fissure lasting more than six to eight weeks, significant ongoing pain or bleeding, repeated recurrence, or structural signs such as thickened edges or a sentinel skin tag.
The decision should be individualized. A specialist considers the duration and severity of symptoms, previous treatments, recurrence and the patient’s overall health before recommending an operation.
One surgical option described by the clinic is lateral internal sphincterotomy. The procedure involves releasing part of the internal anal sphincter to reduce persistent muscle spasm and improve the conditions required for healing.
Choosing an Anal Fissure Specialist in Singapore
Selecting an experienced colorectal surgeon is particularly important when symptoms have become chronic or when surgery is being considered. Patients should receive an accurate diagnosis, understand the available non-surgical and surgical options, and have the opportunity to discuss the expected recovery and potential risks.
At Advanced Colorectal and General Surgery, treatment is led by Dr Leong Quor Meng at Mount Alvernia Hospital. The clinic provides assessment and treatment for acute and chronic anal fissures, including lateral internal sphincterotomy when indicated. It also provides diagnostic colonoscopy and gastroscopy when further investigation is clinically appropriate.
About Dr Leong Quor Meng
Anal fissure surgeon – Dr Leong Quor Meng is a general and colorectal surgeon in Singapore with more than two decades of surgical experience. According to the clinic, he graduated from the University of London in 2000, obtained membership with the Royal College of Surgeons of Edinburgh in 2003, and began Advanced Specialist Training in 2005. He passed his fellowship examinations in 2008.
In 2010, Dr Leong received a Ministry of Health HMDP scholarship for training in laparoscopic and robotic colorectal surgery at Korea University under Professor Kim Seon Hahn. His practice covers a broad range of colorectal and general surgical conditions.
The clinic also states that Dr Leong has performed more than 10,000 diagnostic and therapeutic endoscopic procedures and provides colonoscopy when further investigation is required. For suitable patients requiring fissure surgery, lateral internal sphincterotomy can be performed as a day procedure.
Recovery After Anal Fissure Surgery
Recovery depends on the individual procedure and patient, but the clinic reports that patients undergoing lateral internal sphincterotomy generally experience a significant reduction in pain within the first week or two.
Maintaining soft, regular stools is an important part of recovery. Patients may be advised to use stool softeners, maintain adequate fibre and fluid intake, and continue sitz baths where appropriate. The clinic states that many patients can return to desk-based work and light activities within approximately three to five days, while heavier activities may need to be avoided for longer.
Follow-up allows the surgeon to monitor healing and address concerns such as increasing bleeding, infection symptoms, difficulty passing urine or unexpected changes in bowel control.
When Should You See a Colorectal Surgeon?
Persistent or severe pain during bowel movements, recurrent bleeding, symptoms lasting more than a few weeks, or a lack of improvement with home treatment are reasons to seek medical assessment.
Early evaluation can be useful because an acute fissure may be more responsive to conservative treatment, while chronic fissures can develop structural changes and persistent sphincter spasm that make healing more difficult.
For patients in Singapore looking for an Anal fissure surgeon – Dr Leong Quor Meng offers an approach that begins with diagnosis and conservative management where appropriate, while providing surgical treatment when symptoms persist or the condition requires a more definitive intervention.
