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5-ASAs (aminosalicylates)

Last full review: July 2026

Next review date: July 2029

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5-ASAs are a type of medicine used to treat Ulcerative Colitis. They are also sometimes used in mild forms of Crohn’s Disease. You may have just heard of the name mesalazine, as this is the most common type of 5-ASA. But there are other types of 5-ASAs too. 5-ASAs are also called aminosalicylates.

Whether you take 5-ASAs, are thinking about taking them or just want to find out more, this information is for you. It can help you find out what to expect from this treatment.

This information is about 5-ASAs in general. It should not replace advice from your IBD team.

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Key facts about 5-ASAs

  • Mesalazine is the most common 5-ASA. But there are other types too. You may also hear them called aminosalicylates.
  • 5-ASAs are often a first treatment for people with Ulcerative Colitis. They are sometimes used to help manage mild forms of Crohn’s Disease, but this is less common.
  • You can take 5-ASAs by mouth as a tablet, capsule or granules. You can also take them by inserting a suppository or enema into your bottom.
  • 5-ASAs work by helping to ease inflammation in the bowel. This allows damaged tissue to heal.
  • 5-ASAs aim to get symptoms under control and keep them under control.
  • 5-ASAs are not immunosuppressants. This means unlike some other medicines for Crohn’s and Colitis, they do not affect how your immune system works.

More Information

  • 5-ASAs, including mesalazine, are a group of medicines that work directly in your bowel to ease inflammation. They are thought to do this by affecting the chemicals in your body that cause inflammation. Lowering inflammation helps to stop damage to your bowel tissue and ease symptoms of Ulcerative Colitis or Crohn’s. It may also allow damaged tissue in your bowel to heal and repair itself.

    5-ASAs work directly on your bowel lining. They are not immunosuppressants. This means they do not affect how your immune system works in the rest of your body.

  • There are 4 main types of 5-ASA available in the UK, listed below. Each one may be available by their medical or generic name, as well as by one or more brand name. We have more information about different names for medicines in our information on taking medicines.

    5-ASAs in the UK include:

    • Mesalazine – also known by the brand names Asacol, Mezavant, Octasa, Pentasa, Salcrozine, Salofalk, Zintasa, Zyduco
    • Olsalazine – also known by the brand name Dipentum
    • Balsalazide – also known by the brand name Colazide
    • Sulfasalazine - no brand names

    If you’re not sure which medicine you have, ask someone from your IBD team to explain.

    Some 5-ASAs also come in different forms, or formulations. These may target different parts of your gut. For example:

    • Slow-release tablets or granules that you take by mouth. These are sometimes called modified release or prolonged release. They are designed to release medicine in specific parts of your gut.
    • Suppositories or enemas that you insert into your bottom. These treat inflammation at the end of your colon and rectum.

    Sometimes, you may take 5-ASAs by mouth and as a suppository or enema at the same time. We have more about different formulations of medicines and how to take them in the section below, How to take 5-ASAs.

    What type will I have?

    All 5-ASAs work in slightly different ways, including the parts of the gut that they target. Your doctor may suggest a certain type or brand of 5-ASA, depending on where you have inflammation.

    The type of 5-ASA and brand you are prescribed may also depend on guidelines, costs and availability in your local area. Tell the healthcare professional responsible for prescribing your medicine if you have a preference about the type you take. For example, whether you prefer granules to swallowing tablets. They will be able to recommend which type or brand is most suitable for you.

    “”

    I felt suppositories were very intrusive and were affecting my life. I arranged to see my IBD team and asked if I could be changed to tablets. This was a life changer for me. I would advise anyone with questions to seek help from their IBD team, don’t suffer in silence.

    Lisa

    Living with Ulcerative Colitis

    Can I switch types or brands of 5-ASA?

    If you find a type or brand of 5-ASA that works well for you, your doctor will usually aim to keep you on the same one. Sometimes, there may be supply issues with certain brands. This may mean you may need to switch to a different brand or type of 5-ASA. Your pharmacist may be able to advise on this, or they may need to contact your IBD team for further advice.

    Let your pharmacist or IBD team know about any changes in your symptoms after you have switched treatments.

    If a particular type or brand of 5-ASA is not working well for you, talk to your IBD team. You may be able to try a different 5-ASA. Or, if 5-ASAs are not helping, you may need a different type of treatment.

  • 5-ASAs are usually used to treat Ulcerative Colitis in adults. Some types of 5-ASAs are also suitable for children and young people. If you have mild to moderate Ulcerative Colitis, your IBD team might suggest a 5-ASA: 

    • As a treatment to get symptoms under control during a flare-up
    • To keep symptoms under control and help prevent flare-ups of Ulcerative Colitis longer-term

    5-ASAs are not commonly prescribed for Crohn’s. They may sometimes be prescribed for mild Crohn’s to help get your symptoms under control. Your IBD team may suggest them if you cannot take steroids, or prefer not to take them.

    5-ASAs are generally not recommended for Microscopic Colitis. Studies have not shown them to be effective.

    If you are not sure if 5-ASAs are suitable for you, talk to your IBD team. They will be able to talk you through your options and help guide you.

    5-ASAs may not be suitable for everyone. You may not be able to take 5-ASAs if you:

    • Have very poor kidney function
    • Have severe liver disease
    • Are allergic to any of the ingredients

    Certain other health conditions may also sometimes affect risk. Your doctor will check whether 5-ASAs are safe for you. If you are not sure if 5-ASAs are suitable for you, talk to your IBD team.

    You’ll usually need some tests to check if 5-ASAs are suitable for you. These include blood tests to see how well your kidneys and liver are working.

  • Your IBD team will discuss your treatment options with you. They might give you a choice of different treatments. It’s important to consider the possible benefits and risks of all your treatment options. Think about what your goal from treatment is, and what is most important to you. Things you may want to consider for each option include:

    • How you will take it
    • How often you need to take it
    • How well it works
    • How quickly it may work
    • Side effects you could get
    • Whether you need ongoing tests or checks
    • Other medicines you are taking
    • If you are planning to get pregnant or breastfeed in the next few years
    • Where you will get your medicines from
    • Whether there is a prescription charge for the medicine

    You do not have to think about these things or make the decision on your own. Your IBD team can talk it through with you. You might find it helpful to prepare before any appointments with your IBD team. Our appointment guide has a list of questions you might want to ask during your appointment. It can help you focus on what matters most to you. You might find our information about other medicines and surgery for Colitis helpful too.

    Medicine Tool

    Use this tool to understand more about potential treatment options that suit your needs. The tool is designed to help you:

    • Understand the differences between types of medicines
    • Explore different treatment options based on your personal preferences
    • Feel empowered to discuss medicine options with your IBD team

  • 5-ASAs often work well at getting and keeping symptoms under control in people with mild to moderate Ulcerative Colitis. But they do not work for everyone. What is right for one person may not be right for someone else.

    Below, we show the results of research reviews that looked at how well 5-ASAs work in Ulcerative Colitis. The reviews combined results from studies comparing 5-ASAs to a placebo. A placebo is something that looks the same as the treatment but does not have any medicine in it.

    The results show what happened in the people who took part in the studies. Your experience may be different. This is because research studies do not always reflect real life. Many things can affect how well a medicine works, and everyone is different.

    You can find out more about research studies for medicines in our information on how we talk about the effectiveness of medicines.

    Getting Ulcerative Colitis under control

    Two research reviews looked at how well 5-ASAs got symptoms under control in people with Ulcerative Colitis. This means how well they treated a flare-up.

    • One looked at rectal 5-ASAs, which you insert into your bottom. It included studies in people who had Ulcerative Colitis in the lower parts of their colon and rectum.
    • The other looked at oral 5-ASAs, which you take by mouth.

    Both research reviews found that 5-ASAs worked better than placebo in getting Ulcerative Colitis under control.

    The review of rectal 5-ASAs found that after 2 to 8 weeks of treatment:

    • About 75 in 100, or 75% of people taking a rectal 5-ASA had at least some improvement in their symptoms. This included those who had symptoms completely under control. For people who took placebo, about 29 in 100, or 29% had at least some improvement in symptoms.
    • About 25 in 100, or 25% of people taking a rectal 5-ASA had no improvement in their symptoms. This is compared with 71 in 100 or 71% of people taking a placebo. 

    The bar chart below shows how these results compare for rectal 5-ASAs and placebo, after 2 to 8 weeks of treatment.

    Bar chart to show people who had symptoms under control for rectal 5-ASAs vs placebo

    The review of oral 5-ASAs found that after 6 to 12 weeks of treatment:

    • Around 56 in 100, or 56% of people who took an oral 5-ASA had at least some improvement in symptoms. This included those who had symptoms completely under control. For those taking placebo, 35 in 100, or 35% had some improvement in symptoms.
    • Around 44 in 100, or 44% of people who took an oral 5-ASA did not have any improvement in symptoms. This compared to 65 in 100 or 65% of people taking a placebo.

    The bar chart below shows how these results compare for oral 5-ASAs and placebo, after 6 to 12 weeks of treatment.

    Bar chart to show people who had symptoms under control for oral 5-ASAs vs placebo

    Keeping Ulcerative Colitis under control

    Two research reviews looked at how well 5-ASAs kept symptoms under control in people with Ulcerative Colitis. This means how well they prevented further flare-ups. 

    • One looked at rectal 5-ASAs, which you insert into your bottom. It included studies in people who had Ulcerative Colitis in the lower parts of their colon and rectum.
    • The other looked at oral 5-ASAs, which you take by mouth.

    Both research reviews found that 5-ASAs worked better than placebo to keep Ulcerative Colitis under control and prevent flare-ups.

    The study looking at rectal 5-ASAs found that after 1 year of treatment:

    • Around 62 in 100, or 62% of people who took a 5-ASA had symptoms completely under control. This compared to 30 in 100, or 30% of people who took a placebo.
    • Around 38 in 100, or 38% of people who took a 5-ASA no longer had symptoms completely under control. For people taking placebo, this was 70 in 100 or 70% of people.

    The bar chart below shows how these results compare for rectal 5-ASAs and placebo after a year of treatment.

    Bar chart to show people who still had symptoms under control after a year for rectal 5-ASAs vs placebo

    The study looking at oral 5-ASAs found that after 6 to 12 months of treatment:

    • About 63 in 100, or 63% of people who took a 5-ASA had Ulcerative Colitis symptoms completely under control. This is compared with 48 in 100, or 48% of people who took placebo.
    • About 37 in 100, or 37% of people who took a 5-ASA no longer had symptoms completely under control. For those who took a placebo, this was 52 in 100 or 52% of people.

    The bar chart below shows how these results compare for oral 5-ASAs and placebo after 6 to 12 months of treatment.

    Bar chart to show people who still had symptoms under control after 6mths to a year for oral 5-ASAs vs placebo

  • 5-ASAs are not commonly prescribed for Crohn’s. This is because they are not very effective at getting symptoms of Crohn’s under control or keeping them under control.

    Studies of 5-ASAs in people with Crohn’s have found:

    • Sulfasalazine may provide a small benefit for people with mild to moderate Crohn’s in getting symptoms under control. This is mainly in people with Crohn’s in the large bowel, sometimes known as Crohn’s Colitis. But it does not work as well as steroids.
    • Mesalazine is not effective at getting Crohn’s symptoms under control.
    • 5-ASAs are not effective at keeping Crohn’s symptoms under control. 
    •  5-ASAs are slightly more effective than placebo in keeping symptoms under control after surgery for Crohn’s.

  • Everyone responds differently to a new medicine. Some people with Ulcerative Colitis find that their symptoms start to improve within a week of starting 5-ASAs. It can be a few days for rectal 5-ASAs, which you insert in your bottom. But with any 5-ASA it can take 4 to 6 weeks, or even longer, to get symptoms completely under control.

    It’s possible that after this time 5-ASAs may still not have worked for you. It can be difficult waiting to see whether a new medicine works for you. You can still ask for help and support during this time. If you need support or become more unwell, contact your GP or IBD team. Our helpline service may also be able to signpost you towards the right support.

    If a 5-ASA does not help to control your symptoms, your IBD team might suggest switching to a different type or brand of 5-ASA. Or, they may suggest changing to a different treatment. See the section below on Stopping or changing treatment for more information.

  • Types of formulation

    5-ASAs come in different forms. These include:

    • Tablets and capsules
    • Granules
    • Suppositories and enemas

    Which type you have depends on which part, or how much of your gut is affected by Ulcerative Colitis or Crohn’s. Your doctor will let you know which type would work best for you.

    You may have one form of 5-ASA at a time, or a combination, depending on your situation. Taking a combination can be more effective than either treatment alone.

    Your doctor may suggest that you try different combinations of 5-ASAs until you find something that works well for you.

    Tablets and capsules

    Tablets and capsules are oral medicines that you take by mouth.

    Many brands of 5-ASAs have a special coating around the tablets. This allows the medicine to release in a specific area, or areas of your gut. You should swallow them whole with a glass of water. It’s important you do not chew, cut or crush the tablets, as this could destroy the coating. This could stop the medicine releasing in the right area of your gut.

    You can cut, but not crush, some brands of tablet such as Pentasa.

    Always check the leaflet that comes with your medicine.

    Granules

    5-ASA granules also have a special coating, designed to control where the medicine is released. You take granules by placing them on your tongue and swallowing with plenty of water. If you find granules difficult to swallow with water, try swallowing them with soft food such as yoghurt. You should not chew granules. They are a good option for people who cannot swallow tablets or capsules easily.

    Suppositories and enemas

    Suppositories and enemas are medicines that you insert into your bottom. They can treat the lower parts of your large bowel. These areas can be harder to treat with oral medicines. Suppositories and enemas are also less likely to cause side effects than oral medicines.

    • Suppositories are small, waxy, bullet-shaped capsules that you insert into your bottom. They dissolve at body temperature.
    • Enemas come in different forms, including liquid or foam. You insert them into your bottom, using an applicator.

    Foam enemas are often easier to use than liquid enemas, especially if you find it difficult to hold in a liquid enema. Liquid enemas can usually travel further along your colon. This can be helpful if you have inflammation higher up in your colon. 

    You may have some discomfort using suppositories or enemas at first, especially if you have lots of inflammation in your rectum. You might also find them difficult to use. It’s worth taking some time to read the patient information leaflet that comes with your medicine to check your technique.

    Find out more about how to use rectal products, like suppositories and enemas. Talk to your IBD team if you’re struggling to use suppositories or enemas. They will be able to support you.

    What dose to take

    The healthcare professional who prescribes your medicine will tell you the dose of 5-ASA you need to take. It usually depends on which brand of 5-ASA you are taking, as well as how active your condition is. Your IBD team may advise you to increase or decrease your dose, depending on how you respond. They may also change your dose if your condition changes over time.

    For oral 5-ASAs:

    • You are usually started on a higher dose to get your symptoms under control.
    • Once your symptoms are under control, your dose is then usually lowered to a maintenance dose. This should help to keep your symptoms under control.
    • Your dose may be increased again if you have a flare-up of symptoms.

    Oral 5-ASAs are often prescribed in 2 or 3 doses during the day. You may also have the option to take the medicine as one, bigger daily dose. There are some once-a-day brands available. Some people may find it easier to take their medicine once a day. It may also be more effective in keeping symptoms under control. But there can be a higher risk of side effects.

    For suppositories and enemas:

    • The dose tends to stay the same, whether you’re taking them to get symptoms under control, or keep symptoms under control.
    • Your IBD team may recommend having them every day. Or you may have them less frequently, such as 2 or 3 times a week.

    Check with your IBD team if you’re not sure about the dose you should be taking.

    If you forget to take a dose, follow any instructions in the information leaflet that comes with your medicine. You may need to take it as soon as you remember. Or you may need to wait until your next dose is due. Do not take a double dose to make up for a forgotten dose.

    Taking your 5-ASA regularly as advised by your doctor is important, even when you feel well. Missing doses can increase the risk of flare-ups.

  • All medicines can have side effects, but not everyone will get them. If you do get side effects with 5-ASAs, they’re usually quite mild and there are ways to manage them. They will usually go away on their own or after you stop taking treatment. Others may be more serious and could need treatment.

    The tests and checks you have during treatment can help to spot some of these side effects. We have more on this in the next section, Tests and checks with 5-ASAs.

    What to do if you have a side effect

    Let your IBD team know if you are worried about any side effects you get while taking 5-ASAs.

    We also encourage you to report any side effects to the Medicines and Healthcare Products Regulatory Agency (MHRA). You can do this through the Yellow Card scheme online or by downloading the MHRA Yellow Card app. This helps collect safety information about medicines. 

    Some people may get side effects that have not previously been reported or listed in any information. It can be helpful to write down when you started taking a medicine and when any new symptoms begin. This may help you and your healthcare team work out if a new symptom could be a side effect. 

    Common side effects

    Some of the most common side effects that affect between 1 and 10 in 100 people taking 5-ASAs include:

    • Feeling or being sick
    • Loose and watery poo, known as diarrhoea
    • Headache
    • Stomach pain or discomfort
    • Farting
    • Mild allergic reactions, including a skin rash and itching

    Depending on the particular type of 5-ASA you’re taking, there may be other common side effects. Read the information leaflet that comes with your medicine, or ask your doctor or pharmacist.

    Possible serious side effects

    Rarely, some people who take 5-ASAs develop more serious side effects. These do not happen often, but it is important to know what to look out for. In some cases, you may need treatment for these side effects.

    Contact your doctor or IBD team immediately if you have signs of these problems.

    Intolerance

    Some people have an intolerance to 5-ASAs. This usually happens a few weeks after starting treatment. It means usual symptoms of your condition start to get worse, rather than better. These can include diarrhoea, tummy pain, blood in your poo, high temperature and severe headache. Tell your doctor or IBD team straight away, as you will usually need to stop taking the treatment.

    Kidney problems and kidney stones

    Rarely, 5-ASAs can cause inflammation in your kidneys, which makes them work less well.. Some people get kidney stones when taking mesalazine. Making sure you drink enough fluids while taking treatment can help to avoid this. Signs of kidney problems to look out for include:

    • Change in the colour or amount you pee
    • Swollen legs or arms
    • Sharp, severe pain on one side, under your ribs or on your back

    You will have regular blood tests to check your kidney function. See the section on Tests and checks with 5-ASAs.

    Blood disorders

    Serious blood disorders have been reported in some people taking 5-ASAs. These are very rare. Signs of a blood disorder can include:

    • Unusual bleeding, such as unexpected nosebleeds or bleeding gums
    • Bruising more easily
    • Unusual coloured patches on your skin

    Skin reactions

    Some people can have a serious skin reaction with 5-ASAs. This is also very rare. Signs of a serious skin reaction include a rash with:

    • Flaky, shedding skin
    • Reddish patches that look like targets or circles on your skin
    • Painful or itchy sores or blisters
    • Painful sores in your mouth, nose, throat, genital area or eyes

    Idiopathic intracranial hypertension

    There have been very rare reports of some people taking mesalazine getting a condition called idiopathic intracranial hypertension. This means increased pressure inside your skull. It’s not usually life-threatening, but in some rare cases it can cause serious problems with sight. Tell your doctor or IBD team immediately if you get:

    • Headaches that are becoming more frequent and severe
    • Problems with your sight
    • Ringing or buzzing in your ears
    • Back or neck pain
    • Dizziness

    Allergic reaction

    It’s possible to have a severe allergic reaction to 5-ASAs. This usually happens soon after taking the medicine.

    Call 999 or get emergency medical help if you think you are having a severe allergic reaction.

    Signs to look out for include:

    • Difficulty breathing or swallowing
    • Feeling extremely dizzy or light-headed
    • Swelling of your face, lips, mouth, tongue or throat
    • A rash or raised, itchy patches on your skin, known as hives

    More information on side effects

    We do not cover every side effect of 5-ASAs here. There is information about less common side effects in the Patient Information Leaflet that comes with your medicine. This is also called a Package Leaflet. It should be in the box with your medicine. You can also get it on the Electronic Medicines Compendium website.

  • You will usually have regular blood tests while taking 5-ASAs. This is to monitor how well your medicine is working. It can also help to spot certain side effects early on.

    Your doctor may suggest having a blood test after 3 months of starting treatment, then once a year after that. This is to make sure that your kidneys are still working properly. If you are taking sulfasalazine you may need blood tests more often.

  • You can usually take most other medicines safely with 5-ASAs. But there are some possible interactions that are important to be aware of. You should tell your doctor or IBD team if you are taking any of the following:

    • Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen. Taking these together with 5-ASAs may increase the risk of kidney problems.
    • Azathioprine and mercaptopurine. Taking these at the same time as 5-ASAs may slow down how quickly they are broken down. This may make side effects more likely.
    • Blood thinner medicines such as warfarin or heparin. Taking them with 5-ASAs may increase the risk of bleeding or bruising.

    This is not a full list of all possible interactions with 5-ASAs. There may be more for each type of medicine. Always check the patient information leaflet that comes with your medicine.

    You should also tell your IBD team, doctor or pharmacist if you are taking, or plan to take, any other medicines while you are taking 5-ASAs. This includes:

    • Prescribed medicines
    • Over-the-counter medicines, such as simple painkillers or medicines for cold or flu
    • Multivitamins or supplements
    • Herbal, complementary or alternative remedies

    Read our information on taking medicines to find out more. 

    Vaccinations

    It’s safe to have vaccinations whilst on 5-ASAs. This includes the annual flu jab and COVID-19 vaccines and boosters.

    Before having a vaccine, you should check with your IBD team that it’s suitable for you. This is particularly important if you are also taking other medicines for your IBD. 

  • Alcohol is not known to have any interaction with 5-ASAs. It’s still best to follow NHS guidance on drinking alcohol to keep the health risks low. It’s recommended not to drink more than 14 units of alcohol a week, on a regular basis.

  • How long to take 5-ASAs

    If 5-ASAs work well for you, you will usually be able to keep taking them long-term. This will help keep your condition under control and lower the risk of flare-ups. Taking 5-ASAs even when you are feeling well is likely to be the most effective way to prevent a flare-up.

    As well as helping with your Ulcerative Colitis symptoms, taking 5-ASAs long-term may help to lower your bowel cancer risk. People living with Ulcerative Colitis or Crohn’s affecting the colon may have a slightly higher risk of getting bowel cancer. There is some evidence that shows that taking 5-ASAs can lower this risk. See our information on bowel cancer risk, or talk to your IBD team if you are concerned about your risk of bowel cancer.

    If you pay for NHS prescriptions, it can be difficult managing the extra health costs that come with taking regular medication. It may be cheaper to get a prescription prepayment certificate. Find out more on our money and finding financial support page. Find out more about long-term treatment for Crohn’s and Colitis in our information on taking medicines.

    When to stop or change treatment

    There are a few reasons why you or your IBD team might suggest stopping or changing treatment with a 5-ASA.

    • Your medicine is not working for you
      You will have regular checks when you start your 5-ASA treatment. If it does not help to get your symptoms under control, your IBD team may suggest changing your dose or trying a different type of 5-ASA. If this still does not help, they might suggest trying a different treatment. If stronger treatments help, you may be able to stop your 5-ASAs.
    • You have side effects
      If you have side effects that are serious or difficult to manage, stopping 5-ASAs might be the best option for you.
    • Your symptoms get worse
      If your condition gets more severe over time, it’s possible that 5-ASAs will not control your symptoms anymore. Your IBD team may then recommend other treatments instead of, or in addition to 5-ASAs.

    If 5-ASAs are not helping to get your symptoms under control, or are causing severe side effects, your doctor may prescribe steroids instead. They can help you manage flare-ups. Steroids may take a few weeks to start working, and you may get side effects from them too. Talk to your IBD team about whether they are suitable for you.

    Your IBD team may suggest the following treatments for Ulcerative Colitis or Crohn’s instead of, or in addition to 5-ASAs:

    Do not stop any treatment without talking to your IBD team first. They will be able to talk to you about what options are available.

  • Fertility

    Most 5-ASAs do not affect fertility. However, there are some types that may affect the male fertility.

    • Sulfasalazine can lower sperm count and how well the sperm move. This is reversible. Sperm often returns to the usual count 2 to 3 months after you stop taking sulfasalazine.
    • Zintasa, one of the brands of mesalazine, is made with a coating that could affect sperm count and movement. If you’re taking Zintasa and this is a concern for you, you may want to try a different brand of mesalazine.

    5-ASAs do not seem to affect fertility in women.

    If you have concerns about your fertility, or you are trying to get pregnant, speak to your IBD team. You can also read more about fertility in our information on reproductive health and fertility. 

    Pregnancy

    The majority of 5-ASAs are considered safe to take during pregnancy. When recommended by your IBD team, continuing treatment with 5-ASAs during pregnancy can help to prevent flare-ups. This may help to reduce risks to your baby.

    The manufacturer of balsalazide, known by the brand name Colazide, recommends avoiding taking it during pregnancy. This is because there has not been much research looking at people taking balsalzide while pregnant. The limited research that is available does not suggest any harmful effects. Your IBD team may suggest continuing to take it for this reason. Talk to your IBD team about this if you are worried.

    If you take sulfasalazine while you’re pregnant, you may need to take a regular high-dose folic acid supplement.

    You should always tell your IBD team if you’re pregnant or planning a pregnancy. They will be able to tell you whether any medicines you are taking are safe to continue.

    See our information on pregnancy and birth for more details. 

    Breastfeeding

    5-ASAs are mostly considered safe to take while breastfeeding.

    If you’re breastfeeding while taking 5-ASAs, it’s possible your baby may get diarrhoea. If this happens, it might be best to stop breastfeeding. Sometimes your IBD team may advise not to take a particular type of 5-ASA when breastfeeding. Talk to your IBD, GP or health visitor about what’s best for you and your baby.

    See our information on postnatal care and breastfeeding for more details. 

  • We understand that taking medicines and managing side effects can be difficult. We’re here to help.

    Our Helpline can answer general questions about treatment options and can help you find support from others with Crohn’s or Colitis. Your IBD team are also there to help. You can talk to them about:

    • Your dosage
    • How they’ll be monitoring you
    • What other medicines options there might be

    You should also get in touch with your IBD team if you have any new symptoms or side effects.

    It can take time to find the medicine that’s right for you. Don’t be afraid to ask questions and seek out extra support when you need it.

    This information is general and does not replace specific advice from your health professional. Talk to your GP or IBD team for information that’s specific to you.

  • We follow strict processes to make sure our information is based on up-to-date evidence and is easy to understand. We produce it with patients, medical advisers and other professionals. It is not intended to replace advice from your own healthcare professional.

    We hope that you’ve found this information helpful. Please email us at evidence@crohnsandcolitis.org.uk if:

    • You have any comments or suggestions for improvement
    • You would like more information about the evidence we use
    • You would like details of any conflicts of interest

    You can also write to us at Crohn’s & Colitis UK, 1 Bishop Square, Hatfield, AL10 9NE. Or you can contact us through our Helpline by calling 0300 222 5700.

    We do not endorse any products mentioned in our information.

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Helpline Service

Last updated: 22/07/2026

Our Helpline team can't take calls, chats or ring you back for the rest of the summer. But you can still reach us by email. 

If you need to contact the team, please email helpline@crohnsandcolitis.org.uk and we'll answer you as soon as possible. 

Thanks for bearing with us.

How Can We Help?

  • We can help you understand Crohn’s and Colitis
  • Listen and talk about living with IBD
  • Help you connect with others in the Crohn’s and Colitis community
  • Give you contact details of specialist organisations
  • We can support you to live well with Crohn’s or Colitis and provide up-to-date, evidence-based information

Please be aware we’re not medically or legally trained. We cannot provide detailed financial or benefits advice or specialist emotional support.

0300 222 5700
Email
LiveChat
or About the Helpline

If you need specific medical advice about your condition, your GP or IBD team will be best placed to help.

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