At a glance
Anal dilatation — also known as Lord’s procedure or manual dilation — is a surgical approach for chronic anal fissure where the internal sphincter is stretched under anaesthesia to reduce spasm and allow the fissure to heal.
It was once one of the most commonly performed procedures for fissures. Over the past two decades, it has largely been replaced by lateral internal sphincterotomy (LIS) in many countries, primarily because LIS offers a more controlled, predictable reduction of sphincter tone with lower rates of continence disturbance.
This guide covers what the procedure involves, why the shift away from it happened, the cases where it is still used, and what to consider if your surgeon offers it as an option.
What the procedure involves
Anal dilatation is performed under general or regional anaesthesia as a day case. The surgeon inserts fingers into the anal canal and gradually stretches the internal sphincter muscle. The degree and duration of the stretch varies by technique.
The original Lord’s procedure, described in the 1960s, involved a vigorous four-finger stretch. This approach has been largely abandoned because of high complication rates. Modern dilatation techniques — sometimes called “standardised anal dilatation” — use a more controlled, gentler approach:
- A calibrated dilator or a limited number of fingers
- A defined endpoint — typically a specific diameter rather than stretching until resistance stops
- Shorter duration of the stretch
- More careful assessment of the patient’s individual sphincter anatomy beforehand
The goal is the same as LIS: to reduce the resting pressure of the internal sphincter so that blood flow to the fissure improves and healing can take place. The difference is in method — stretching versus a precise surgical cut.
Why the shift away from dilatation
The medical community’s move toward LIS and away from dilatation has been driven primarily by outcomes data:
The control problem
The fundamental issue with dilatation is predictability. When a surgeon performs LIS, they make a controlled cut of a defined length in the internal sphincter. The extent of the sphincterotomy can be calibrated to the individual patient.
With dilatation, the degree of sphincter disruption is harder to control. The stretch can cause irregular tears in the sphincter muscle rather than a clean division. These tears may be larger or in different locations than intended. Ultrasound studies after dilatation have shown that the pattern of sphincter disruption is less predictable than after LIS.
Incontinence rates
Multiple studies comparing dilatation with LIS have found higher rates of continence disturbance after dilatation. This includes:
- Higher rates of difficulty with gas control
- Higher rates of minor soiling
- In some older studies using aggressive techniques, significant incontinence
The numbers vary depending on the technique used, the study population, and how incontinence is measured. But the consistent finding is that dilatation carries more risk to continence than LIS — and LIS itself already carries a small risk that many people find anxiety-inducing.
Guideline changes
Based on the accumulated evidence, professional bodies in many countries have moved their guidelines. The National Institute for Health and Care Excellence (NICE) in the UK, for example, recommends LIS as the preferred surgical option for chronic fissure when conservative treatments have failed. Dilatation is typically mentioned as an alternative that should be used with caution.
When dilatation is still used
Despite the general shift, dilatation has not disappeared entirely. There are situations where it may still be offered:
- Surgeon expertise. Some experienced surgeons have refined their dilatation technique over many years and report good outcomes with low complication rates. A surgeon’s individual results matter alongside the broader evidence.
- Standardised techniques. Modern controlled dilatation with calibrated instruments and defined endpoints is a different procedure from the old four-finger stretch. Some research suggests that outcomes with these controlled approaches are closer to LIS outcomes.
- Patient-specific factors. In some cases, the anatomy or the clinical picture may make dilatation a reasonable choice. Your surgeon will assess your individual situation.
- Availability and training. In some healthcare settings, dilatation may be more readily available or more commonly practised than LIS.
What recovery looks like
Recovery after dilatation follows a broadly similar pattern to recovery after other sphincter procedures:
- First few days: Moderate pain, particularly around bowel movements. Sitz baths and pain relief are standard.
- First week: Pain gradually improving. Stool softeners to prevent straining. The wound from the stretch is internal, so there is no external wound to care for — though some people experience bruising or swelling around the anus.
- Weeks two to four: Continued improvement. Most people return to normal activities within two to three weeks.
- Continence monitoring: Your surgical team will ask about bowel control during follow-up appointments. Any changes should be reported promptly.
Some people report a very quick recovery — particularly those who had a controlled dilatation with a relatively gentle approach. Others describe a recovery similar in intensity to LIS. The variability reflects the variability in the procedure itself.
Discussing dilatation with your surgeon
If your surgeon recommends dilatation, or if you have been offered a choice between dilatation and LIS, there are some questions worth considering:
- What technique will you use? Understanding whether this is a modern standardised approach or a more traditional technique matters.
- What are your personal outcomes? A surgeon who has performed hundreds of controlled dilatations with consistently good results and low complication rates may offer a different risk profile than the average from published studies.
- How does this compare to LIS for my specific situation? There may be reasons related to your anatomy or history that make one option more suitable than the other.
- What is the incontinence risk with the technique you use? Ask for their own data, not just published averages.
- What happens if this does not work? Understanding the next steps if dilatation does not resolve the fissure is part of making an informed decision.
The goal is not to challenge your surgeon, but to understand the reasoning behind their recommendation. Surgeons who offer dilatation are aware of the broader evidence and should be able to explain why they believe it is the right choice for your situation.
A balanced view
It would be easy to read the evidence and conclude that dilatation should never be done. That oversimplifies things.
The old-style aggressive dilatation rightly fell out of favour. The evidence is clear that it carried unacceptable incontinence risk. But modern controlled approaches are a different proposition, and some surgeons achieve excellent outcomes with them.
What matters most is that you understand what is being proposed, the reasoning behind it, and the specific risks. If you feel uncertain, seeking a second opinion is always reasonable. And if you have already had a dilatation and are recovering, the same principles of aftercare apply as for any sphincter procedure — stool management, wound care, patience, and monitoring for complications.
When to contact your doctor
Seek medical attention if you experience:
- Heavy bleeding that is not slowing
- Severe or worsening pain, particularly after the first few days
- Fever or chills
- Any change in bowel control — difficulty holding gas, urgency, or soiling
- Any symptom that concerns you
If you notice changes to your bowel control after the procedure, report these at your follow-up appointment even if they seem minor. Early intervention and pelvic floor exercises can help in many cases.