At a glance
When an anal fissure does not heal with basic conservative care alone, a doctor may prescribe a topical ointment to help relax the internal sphincter muscle and improve blood flow to the area. These prescription topicals are one of the most common first-line treatments for fissures that need more than fibre, hydration, and sitz baths.
This page covers how these treatments work, what people report about using them, common side effects, and practical tips that come up frequently in people’s experiences.
How topical treatments work
The internal anal sphincter is a ring of muscle that stays contracted most of the time. In people with fissures, this muscle often goes into spasm, which restricts blood flow to the tear and slows healing.
Prescription topical treatments work by relaxing that muscle. When the sphincter relaxes:
- Blood flow to the fissure improves
- The wound gets more oxygen and nutrients
- Pain from spasm decreases
- The fissure has a better chance to heal
The ointment is applied directly to the anal area, as directed by your doctor. It works locally — the medication is absorbed through the skin to affect the underlying muscle.
GTN (glyceryl trinitrate)
GTN — also known as nitroglycerin ointment — is the most established topical treatment for anal fissures. It has been used for this purpose for decades and is often the first prescription topical a doctor will try.
What people report about using GTN
- Application — people describe applying a small amount of ointment to the anal area, usually with a finger or finger cot. Your doctor or pharmacist will explain how much to use and where to apply it. Many people say it becomes routine after the first few days.
- Frequency — GTN is typically prescribed for application two or three times a day. Always follow your doctor’s specific instructions.
- Onset — some people notice a reduction in spasm and pain within the first few days. Others say it took a week or two before they felt a meaningful difference.
- Duration — most courses run for 6 to 8 weeks. Your doctor will advise on how long to continue.
The headache question
Headaches are the most commonly reported side effect of GTN. This comes up in nearly every conversation about the treatment.
What people describe:
- Intensity varies — some people get mild headaches that pass quickly. Others describe throbbing headaches that are difficult to manage.
- Timing — headaches typically start within minutes of application and may last 30 minutes to a few hours
- They often improve — many people report that headaches become less severe after the first week or two as the body adjusts
- Some people cannot tolerate them — for a portion of people, the headaches remain severe enough that they need to switch to a different treatment
The headaches happen because GTN is a vasodilator — it widens blood vessels. The same mechanism that helps the fissure heal also affects blood vessels elsewhere, including in the head.
If headaches are severe, talk to your doctor. They may suggest adjustments or recommend switching to a different topical treatment. Do not stop treatment on your own without discussing it first.
Diltiazem
Diltiazem is a calcium channel blocker that works differently from GTN but achieves a similar result — relaxing the internal sphincter to improve blood flow. Many people are prescribed diltiazem either as a first choice or after finding GTN headaches too difficult to manage.
What people report about diltiazem
- Fewer headaches — this is the main reason many people switch. Diltiazem does not typically cause the same intensity of headaches as GTN.
- Application — similar to GTN. A small amount applied to the anal area, usually two to three times daily as prescribed.
- Effectiveness — people generally report similar healing outcomes to GTN. It is considered an effective alternative, not a lesser option.
- Texture — some people note that diltiazem ointment has a different consistency to GTN. This is a minor practical difference.
Diltiazem and skin reactions
A portion of people report skin irritation or rash with diltiazem. This is a recognised side effect that comes up regularly in people’s experiences.
What people describe:
- Localised redness or irritation around the application area
- An itchy rash that may develop after days or weeks of use
- For most people, the irritation is mild and manageable
- In some cases, it is significant enough to require switching treatments
If you develop a rash or skin reaction, let your doctor know. They can advise whether to continue, adjust, or change treatments.
Nifedipine
Nifedipine is another calcium channel blocker sometimes prescribed as a topical treatment for fissures. It works by a similar mechanism to diltiazem — relaxing smooth muscle to reduce sphincter spasm.
People who have used nifedipine report:
- A side effect profile similar to diltiazem, with fewer headaches than GTN
- It is less commonly prescribed than GTN or diltiazem in many regions, but some doctors prefer it
- Application is similar to the other topical treatments
- Your doctor may recommend nifedipine based on availability, local prescribing practices, or your response to other treatments
Rectogesic
Rectogesic is a brand name for GTN ointment used in some countries, particularly in the UK and Australia. If your doctor has prescribed Rectogesic, the information in the GTN section above applies to you.
People sometimes search specifically for this brand name, so it is worth knowing that:
- Rectogesic is a GTN ointment — the same active ingredient described above
- The same side effects, application approach, and practical tips apply
- Your pharmacist can answer questions about the specific product
Practical tips people share
These tips come up repeatedly in people’s experiences with topical treatments. They are not medical instructions — always follow your doctor’s guidance.
Application
- Use a finger cot or disposable glove — many people find this more hygienic and easier to clean up. It also prevents the medication from being absorbed through your finger.
- Apply a thin layer — more is not necessarily better. People consistently report that a small amount as directed is sufficient.
- Wash hands thoroughly after application, even if you used a glove. GTN in particular can cause headaches if it contacts other skin.
Timing
- Before bed is popular — many people find applying before sleep works well. You are lying down, which reduces dizziness risk, and any headache may pass while you sleep.
- After a sitz bath — some people apply their treatment after a sitz bath, when the area is clean and warm. Some find this helps with absorption.
- Build it into routine — people who report the best consistency tie application to existing habits (after bathroom visits, before bed, after showering).
Managing comfort
- Wear a liner or pad — topical ointments can transfer to underwear. Many people use a thin panty liner or pad to keep things comfortable.
- Keep the tube accessible — storing it where you will remember it (bathroom cabinet, bedside table) helps with consistency
- Room temperature — some people find the ointment easier to apply when it is not cold. Keeping it at room temperature rather than in the fridge can help, unless your pharmacist advises otherwise.
Common side effects
Side effects are a normal part of these treatments. Experiencing them does not mean something is wrong — it means the medication is active in your body. That said, side effects that are severe or worsening should always be discussed with your doctor.
GTN side effects
- Headaches — the most common. Can range from mild to severe. Often improve over time.
- Dizziness or lightheadedness — particularly when standing up quickly after application
- Flushing — a warm feeling or redness, usually temporary
- Local irritation — some soreness or burning at the application site
Diltiazem and nifedipine side effects
- Skin irritation or rash — more common with calcium channel blockers than with GTN
- Headaches — can occur but are generally reported as less frequent and less severe than with GTN
- Local itching — some people describe itching around the application area
- Mild burning — a brief sensation after application that usually settles
How long to use them
Most topical treatments for fissures are prescribed for a course of 6 to 8 weeks. This is important to understand because:
- Stopping too early is a common mistake — people frequently report that they felt better after 2 or 3 weeks and stopped, only for the fissure to return. Feeling better does not mean the fissure has fully healed.
- Consistency matters — regular application as directed throughout the full course gives the fissure the best chance to close completely
- Your doctor sets the timeline — they may extend treatment beyond 8 weeks or stop it earlier depending on how things are going
- Follow-up is valuable — checking in with your doctor toward the end of the course helps determine whether the fissure has healed or whether next steps are needed
People often describe a pattern where pain and bleeding improve within the first few weeks, but complete healing takes the full course or longer. Patience and persistence come up as themes in nearly every experience shared.
When topicals are not enough
Topical treatments work for many people, but not for everyone. If a fissure has not healed after a full course of topical treatment, your doctor will discuss next options.
Common next steps include:
- Trying a different topical — if you used GTN, switching to diltiazem (or vice versa) is sometimes recommended
- Botox injection — a procedure that temporarily relaxes the sphincter for 2 to 3 months, giving the fissure another window to heal
- Surgical options — LIS (lateral internal sphincterotomy) or fissurectomy may be discussed for fissures that have not responded to other treatments
Not healing with topicals does not mean nothing will work. It means the fissure needs a different approach. Many people describe eventually finding the treatment that worked for them after an initial topical course was not enough.
The Sudocrem and Neosporin question
These products come up frequently in discussions about fissure care, so they are worth addressing directly.
- Sudocrem is a barrier cream. It can protect irritated skin and some people find it soothing. It does not relax the sphincter or treat the underlying cause of a fissure.
- Neosporin is a topical antibiotic. Fissures are not typically caused by infection, so antibiotic ointment does not address the core problem.
- Vaseline and other barrier products — some people use these to reduce friction during bowel movements. They may provide comfort but are not treatments for fissures.
People try these products because they are accessible, affordable, and feel like doing something. That is understandable. They may offer some surface-level comfort, but they are not substitutes for the prescription topical treatments described above. If your fissure needs more than conservative care, a conversation with your doctor about prescription options is the next step.
Questions to ask your prescriber
If you have been prescribed a topical treatment, or are considering asking about one, useful things to discuss:
- Which topical they recommend for your situation and why
- What to do if side effects are difficult to manage
- How you will know whether the treatment is working
- What the plan is if the first topical does not lead to healing
- Whether to continue conservative care (fibre, sitz baths, hydration) alongside the prescription — the answer is almost always yes
If you experience severe headache or dizziness, fainting, an allergic reaction or spreading rash, pain that is worsening despite treatment, or bleeding that increases, seek medical care.