At a glance
Being prescribed a topical treatment for an anal fissure is common. Knowing how to actually apply it — that part is less straightforward than most people expect. The instructions that come with the medication can be vague, and many people leave the pharmacy feeling unsure.
This guide covers how people describe applying GTN, diltiazem, and nifedipine, based on patterns from hundreds of shared experiences. It is a companion to our broader guide on topical treatments for fissures, which covers how these medications work and what to expect overall.
This is not a replacement for your prescriber’s instructions. Always follow the specific guidance you were given. What follows reflects what people commonly report and the practical questions that come up most often.
What these treatments actually do
All three common topical fissure treatments — GTN (glyceryl trinitrate), diltiazem, and nifedipine — work by relaxing the internal anal sphincter. That tight ring of muscle goes into spasm around the fissure, which restricts blood flow and prevents healing.
The cream or ointment delivers the medication through the skin to the muscle underneath. When the sphincter relaxes:
- Blood flow to the fissure improves
- Spasm-related pain decreases
- The tear gets a better chance to close
The medication works locally. You are not treating your whole body — you are getting a muscle relaxant to the specific area that needs it.
How people describe applying these treatments
This is the question that generates the most uncertainty. Here is what people commonly report.
Where to apply
Most topical fissure treatments are applied to and just inside the anal verge — the outside of the anus and the very start of the anal canal. Not deep inside.
People commonly describe:
- Using a fingertip to apply a thin layer around the outside of the anus
- Gently pressing a small amount just inside the opening — roughly to the first knuckle
- The fissure itself is usually at or just inside the anal margin, so the medication does not need to go far
If your doctor has given specific instructions about placement, those take priority.
How much to use
More is not better. People consistently report that a pea-sized amount or less is sufficient per application.
- For GTN/Rectogesic, the packaging often mentions a measured dose line or a small strip along the finger
- For compounded diltiazem or nifedipine, a similar small amount is typical
- Excess cream does not speed healing — it just increases the chance of side effects and mess
Application technique
What people describe as their routine:
- Wash hands thoroughly before and after
- Use a finger cot or disposable glove — this prevents the medication absorbing through your finger (particularly important with GTN, which can cause headaches from skin contact)
- Apply a small amount to the fingertip
- Gently apply around and just inside the anus — no need to push deeply
- Wash hands again even after using a glove
- Use a thin liner or pad in your underwear to catch any residue
Some people describe using a cotton bud or applicator tip instead of a finger. This is a personal preference — what matters is that the medication reaches the area.
How often
Most topical fissure treatments are prescribed for application two or three times daily. Common timing patterns people describe:
- Morning, after work, and before bed
- After each bowel movement plus before bed
- Tied to existing routines to help with consistency
Your prescriber will specify the frequency. Spacing applications roughly evenly through the day is a common suggestion.
Managing side effects
Side effects are a major reason people struggle with these treatments. Understanding what to expect and how others manage them makes a real difference to sticking with the course.
GTN headaches
This is the single most discussed side effect in the fissure treatment space. GTN relaxes blood vessels — that is how it works on the sphincter, but it also affects blood vessels elsewhere, including in the head.
What people report:
- Timing — headaches typically start within 5 to 15 minutes of application
- Duration — anywhere from 20 minutes to several hours
- Intensity — ranges from a dull ache to a severe, throbbing headache
- The first week is often the worst — many people report headaches becoming more tolerable as their body adjusts
Strategies people describe for managing GTN headaches:
- Take paracetamol before applying — many people report taking it 20 to 30 minutes ahead of application
- Start with a smaller amount — some people begin with half the prescribed dose for the first few days, then build up. Discuss this approach with your prescriber.
- Apply before bed — lying down reduces dizziness risk, and the headache may pass while you sleep
- Stay hydrated — dehydration seems to worsen the headaches based on what people report
- Give it time — the first 5 to 7 days are commonly described as the adjustment period
If headaches remain severe after 7 to 10 days, speak to your doctor. Switching to diltiazem is a common next step — it works by a different mechanism and typically causes fewer headaches.
Burning or stinging on application
Some people describe a brief burning or stinging sensation when applying any of these treatments. This is particularly common with:
- Application to broken or irritated skin
- The first few applications when the area is most sensitive
- Diltiazem and nifedipine formulations in some people
This usually settles within a few minutes. If burning is intense or worsening with each application, let your doctor know.
The diltiazem itch
Diltiazem is often prescribed because it avoids the severe headaches of GTN. However, some people develop a localised itch or mild rash around the application area.
What people describe:
- Onset — may appear after days or weeks of use, not necessarily immediately
- Character — itching, redness, or a slightly raised rash around the anus
- Severity — mild and tolerable for most, but significant enough to require switching treatments for some
- Management — keeping the area clean and dry, using unscented products, and not scratching are common suggestions
If the itch is worsening, the rash is spreading beyond the application area, or the skin is breaking down, talk to your doctor. They may adjust the formulation, try nifedipine instead, or explore other options.
Dizziness and lightheadedness
GTN in particular can cause a drop in blood pressure. People describe:
- Feeling lightheaded when standing up after application
- Brief dizziness that passes within a few minutes
- This being worse in warm environments or after a hot sitz bath
Practical tips people share:
- Apply while sitting or lying down
- Wait a few minutes before standing up
- Avoid applying immediately after a very hot bath
Common mistakes people report
These come up repeatedly in people’s accounts of using topical treatments. Avoiding them may help your treatment work better.
Stopping too early
This is the single most common mistake people describe. Pain improves after 2 or 3 weeks, and the temptation to stop is strong. But a fissure that feels better is not necessarily a fissure that has fully healed.
Most courses are 6 to 8 weeks for a reason. People who stop early frequently report the fissure returning — sometimes within days.
Using too much
Applying more cream does not speed healing. It does increase side effects. A small, consistent amount applied regularly is more effective than a large amount applied irregularly.
Inconsistent application
Missing doses or applying at irregular intervals reduces the treatment’s effectiveness. The sphincter needs consistent relaxation to give the fissure a sustained healing window.
People who report the best outcomes consistently mention making application a non-negotiable part of their routine — like brushing teeth.
Not washing hands after applying GTN
GTN is absorbed through skin. If you touch your face, rub your temples, or handle food without washing your hands thoroughly, you may get a headache from the residual medication on your fingers. Gloves help, but washing afterward is still important.
Ignoring side effects rather than discussing them
Some people push through severe headaches or worsening skin reactions without mentioning them to their doctor. There are alternatives available. Side effects that make it impossible to complete a treatment course should always be discussed — switching to a different topical is straightforward and common.
Reapplying after a bowel movement
This question comes up constantly. If you have a bowel movement shortly after applying your treatment, the medication may have been partially or fully wiped away.
What people commonly describe:
- Within an hour of application — most people reapply after cleaning up
- Several hours after application — the medication has likely been absorbed sufficiently, and reapplication at the next scheduled time is reasonable
- General principle — the medication needs to be in contact with the area to work, so if it has clearly been removed, reapplication makes sense
If you are unsure, ask your prescriber for their guidance on this specific scenario. It is a common question and they will have a clear answer for the product they prescribed.
Cream vs ointment — the practical difference
People often wonder whether cream or ointment is better. The answer is mostly about the formulation their prescriber chose, not a personal preference.
- Ointments (like GTN/Rectogesic) have a greasier base. They tend to stay in place longer and may provide a mild barrier effect. They can feel messier.
- Creams (like many compounded diltiazem preparations) absorb more quickly and feel lighter on the skin. They may need slightly more frequent application.
Both deliver the active ingredient effectively. The form matters less than using it consistently and correctly. If the texture of your prescribed treatment makes application difficult or unpleasant, mention it to your pharmacist — sometimes different preparations of the same medication are available.
When to go back to your doctor
Topical treatments require follow-up. These are situations where people commonly describe going back sooner than planned:
- No improvement after 2 to 3 weeks — some change should be noticeable by this point, even if healing is not complete
- Side effects that prevent consistent use — if headaches, itching, or burning make it impossible to apply as directed, there are alternatives
- Symptoms worsening during treatment — increasing pain or bleeding while using the treatment as prescribed warrants a conversation
- New symptoms — anything unexpected that was not present before starting treatment
- Completing the course with lingering symptoms — your doctor needs to assess whether the fissure has healed, partially healed, or needs a different approach
Going back is not failure. Topical treatments work for many people, but not everyone responds to the first one tried. Your doctor expects follow-up and has a plan for next steps.
Questions to bring to your appointment
If you are struggling with application or side effects, practical questions to discuss:
- Can you show me exactly where and how much to apply?
- Should I reapply if I have a bowel movement soon after application?
- What should I do if I miss a dose?
- Is there a different formulation that might cause fewer side effects?
- How will we know if this treatment is working?
- What are the next options if this does not lead to healing?