At a glance
When conservative self-care is not healing a chronic fissure, the next conversation usually involves two main options: topical medications (such as GTN or diltiazem) and botox injection. Both work by relaxing the internal anal sphincter to improve blood flow and allow the fissure to heal — but they do so through different mechanisms, different timelines, and different levels of intervention.
This guide compares the two approaches based on what people commonly describe about each.
How they work
Topical treatments
Topical fissure medications are applied directly to the anal area, typically two to three times daily. The most common are:
- Glyceryl trinitrate (GTN) — releases nitric oxide, which relaxes smooth muscle
- Diltiazem — a calcium channel blocker that relaxes the sphincter
- Nifedipine — similar mechanism to diltiazem
These medications reduce the resting pressure of the sphincter temporarily. The effect lasts as long as the medication is active — typically a few hours per application. By reducing pressure regularly throughout the day, they create conditions for the fissure to heal.
Botox
Botulinum toxin is injected directly into the internal sphincter muscle under anaesthesia. It blocks the nerve signals that maintain sphincter tone, producing a sustained reduction in pressure that lasts three to four months.
The effect builds over one to two weeks as the toxin takes full effect, then gradually wears off as the nerve endings regenerate. The goal is for the fissure to heal during this window of reduced pressure.
Comparing the experiences
Daily routine
Topical: Requires daily application, typically two to three times per day. People describe the routine as manageable but tedious, and the application itself as sometimes uncomfortable.
Botox: No daily treatment routine — the botox works on its own after the injection. Self-care measures (fibre, sitz baths) still apply, but there is no medication to apply daily.
Side effects
Topical: The most commonly reported side effect is headaches, particularly with GTN. Some people describe the headaches as mild; others find them significant enough to affect daily function. Dizziness and flushing are also reported. Diltiazem generally has fewer side effects but may be less effective for some people.
Botox: The most commonly reported concern is temporary difficulty controlling gas or urgency — this is uncommon but important to be aware of. The procedure itself carries the minor risks associated with anaesthesia.
Timeline
Topical: Treatment is typically prescribed for six to eight weeks. Improvement, if it occurs, may be noticeable within two to four weeks. The treatment requires consistent daily application throughout.
Botox: The effect builds over one to two weeks. The full benefit is typically apparent by week two to three. The botox window lasts three to four months, during which the fissure has the opportunity to heal.
Effectiveness
Topical: Healing rates for chronic fissures with topical treatment vary but are generally in the range of forty to sixty per cent, depending on the study and the specific medication.
Botox: Healing rates are generally higher, commonly reported in the range of sixty to eighty per cent for chronic fissures. However, some people do not respond, and recurrence after the botox wears off is possible.
Invasiveness
Topical: Non-invasive. Applied at home. No procedure required.
Botox: Requires a procedure under anaesthesia, typically as a day case. Brief but involves the medical setting, preparation, and a recovery period.
The typical pathway
In most treatment pathways, the progression looks like this:
- Conservative self-care — fibre, fluid, sitz baths
- Topical treatment — if conservative measures do not heal the fissure
- Botox — if topical treatment is not sufficient
- Surgery (LIS) — if botox does not produce lasting healing
Not everyone goes through every step. Some people’s fissures heal with self-care alone. Others go directly to botox based on their clinician’s assessment of the fissure’s severity and their sphincter pressure.
Making the decision
The decision between topical treatment and botox is usually made in consultation with a clinician and depends on several factors:
- Duration of the fissure — longer-standing fissures may be directed to botox sooner
- Severity of symptoms — severe pain and high sphincter pressure may favour botox
- Response to previous treatment — if topical treatments have been tried and failed, botox is the logical next step
- Patient preference — some people prefer to try the less invasive option first; others want the higher efficacy rate and simpler daily routine of botox
- Sphincter pressure — measured high pressure may suggest topical treatments will be insufficient
Both options have a legitimate place in fissure management. Neither is inherently better — the right choice depends on the individual situation.