Last reviewed: September 2023

person holding their stomach in pain

This information is about flare-ups in people aged 16 and over.

This information will explain what a flare-up is and the signs to look out for. It will help you understand what to do:

  • If you think you are having a flare-up
  • To reduce your risk of having a flare-up

If your child is aged under 16 and you think they are having a flare-up, contact their GP or IBD team. Our supporting your child resource has information on signs of a flare-up in children.

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  • Key facts about flare-ups
    • A flare-up is when symptoms come back and you feel unwell.
    • Signs of a flare-up include going for a poo more than 5 times in 24 hours – or more than is normal for you, loose poo or diarrhoea with blood or mucus for more than 3 days and abdominal pain.
    • Everyone experiences flare-ups differently. They can last anywhere from a few days to several months.
    • If you have a personalised care and support plan, follow the guidance given.
    • If you don’t have a care and support plan and are having a flare-up, contact your IBD team or GP.
  • What is a flare-up?

    A flare-up is when symptoms come back and you feel unwell. Everyone experiences flare-ups differently. Your symptoms may also change over time. Flare-ups can last anywhere from a few days to several months and you may have different symptoms during a flare-up than you had when you were first diagnosed.

    Signs of flare-up can include:

    • Going for a poo more than 5 times in 24 hours – or more than is normal for you
    • Loose poo or diarrhoea with any blood or mucus for more than three days
    • Abdominal pain
    • Feeling generally unwell, especially if you have a fever
    • Waking up at night to go to the toilet

    You may also experience symptoms outside the gut during a flare-up such as:

    • Joint pain and swelling (arthritis)
    • Swelling in the eyes
    • Mouth ulcers
    • Skin rashes
    • Fatigue
    • Mental health problems 

    Read our information on managing symptoms to find out more.

  • I'm having a flare-up - what should I do?

    If you have a written personalised care and support plan or your IBD team have agreed with you previously what to do if your symptoms get worse, follow the specific guidance given by your doctor or nurse.

    If you do not have a personalised plan contact your local IBD team or GP via phone or email.  If you are unable to contact your GP or IBD team, call NHS 111 or contact your local out-of-hours service.

    Please be aware that our Helpline is not able to give individual advice on this.

  • When should I seek urgent or emergency care?

    You will know your body and condition better than anyone. If you feel you need urgent care phone 111. If you need emergency care call 999. It's important to go to hospital if you're advised to.

    Go to A&E or call 999 if you:

    • Have severe dehydration or malnourishment
    • Are vomiting up blood
    • Have severe tummy pain, a high temperature and a rapid heartbeat.
    • Are bleeding non-stop from your bottom
    • Have a stoma and think it might be blocked. Signs of stoma blockage include: not passing wind or poo, passing watery poo, nausea, bloating or swelling tummy, tummy cramps, swollen stoma, nausea or vomiting or both.

    All medicines have a small risk of side effects, such as chest pain, rapid heartbeat or hives. If you experience any side effects that you are worried about while taking your medicine, contact your IBD team or your GP as soon as possible.

  • Flare-up guidance - Ulcerative Colitis

    If you have Ulcerative Colitis and are experiencing a flare-up, you may be able to temporarily increase the amount of 5-ASA medicine you take.


    If you decide to do this, it's important to inform your IBD team or GP of any changes as soon as possible by telephone or email. You may also want to check with your healthcare professional first if you are pregnant or have another health condition. 

    If you are taking 5-ASAs, you can take up to the amount below for 8 weeks, unless you have already been told by your healthcare professional not to increase your dose.

    This advice only applies to 5-ASAs, not any other medicine you may be taking.


    • Salofalk: maximum 3g per day                                   
    • Asacol: maximum 4.8g per day
    • Mezavant: maximum 4.8g per day              
    • Pentasa: maximum 4g per day
    • Octasa: maximum 4.8g per day

    You may see your dose in g or mg: 1g = 1000mg, 0.8g = 800mg, 0.5g = 500mg.

    Check the Patient Information Leaflet inside your medicine box or online at medicines.org.uk/emc to find out what dosage is in your medicine.

    Even if your symptoms settle quickly, continue taking your increased dose for 8 weeks then reduce back to your regular dose, unless advised otherwise by your IBD team or GP.

    If you are prescribed suppositories or enemas and you have a supply of these at home, you can start taking these too. You can take these every night as well as increasing your 5-ASA tablets.

    If your symptoms do not improve, contact your IBD team or GP. Our appointment guide has useful tips and tools to help you describe your symptoms and talk about how you are feeling.


    This advice does NOT apply if you have Crohn's. If you have Crohn’s and are having a flare-up, see the previous section: I'm having a flare-up - what should I do?

  • Reducing the risk of a flare-up

    What you can do to reduce the risk of a flare-up

    Taking your medicines as prescribed by your IBD team, even when you feel well, reduces the risk of flare-ups. We don’t yet know what causes flare-ups, but possible triggers include:

    • Disruptions or changes in medicines
    • Ongoing stress
    • Gut infections
    • Taking non-steroidal anti-inflammatory medicines (NSAIDs) such as ibuprofen

    It can help to keep a diary of symptoms to see if you become aware of any triggers for you. You can find one in My Appointments Journal.

  • Staying well

    We want people with Crohn’s and Colitis to feel empowered to manage their condition. Our resources and videos give information on how to manage symptoms, stay as well as possible and where to find emotional and peer support.

    Our top tips for keeping as well as possible are:

    • Continue taking your medication as normal unless your doctor or nurse have advised you otherwise.
    • Ensure you have a good supply of medicines.
    • Stay hydrated. If you are flaring and experiencing diarrhoea, it’s important to make sure you are drinking enough to replace what you have lost, and in doing so getting the right balance of sugars and essential salts into your body to keep hydrated. Our information on dehydration gives tips on preventing dehydration.
    • Eat well. Living with Crohn’s or Colitis may mean making some changes to your diet. You may need to avoid certain foods to help your symptoms or take extra care to make sure you’re getting the right nutrients. There’s no single diet that works for everyone – our food information will help you understand how food affects your condition, so you can make the choices that are right for you.
    • Take rest and sleep. Our fatigue resource has tips on exercise and managing fatigue.
    • Quit smoking
    • Avoid NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen.
    • Protect your emotional and mental wellbeing. There are a number of excellent resources from organisations like MIND and the Mental Health Foundation. However, if you are struggling with your Crohn’s or Colitis, you may want to read our information on mental health and wellbeing.
  • Getting support from your GP or healthcare professional

    If you are unable to get in contact with your IBD team, your GP may be able to help. There are a number of resources that you may want to show your GP. The Royal College of General Practitioners (RCGP) and Crohn’s & Colitis UK have created an IBD toolkit, a guide to IBD and managing flares for GPs. We also have podcasts and webinars available in our resources for healthcare professionals.

  • About this information

    We follow strict processes to make sure our information is based on up-to-date evidence and easy to understand.

    Please email us at evidence@crohnsandcolitis.org.uk if:

    • You have any comments or suggestions for improvements
    • You would like more information about the sources of 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 contact us through our Helpline: 0300 222 5700


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Helpline service


We know it can be difficult to live with, or support someone living with these conditions. But you’re not alone. We provide up-to-date, evidence-based information and can support you to live well with Crohn’s or Colitis.

Our helpline team can help by:

  • Providing information about Crohn’s and Colitis.

  • Listening and talking through your situation.

  • Helping you to find support from others in the Crohn’s and Colitis community.

  • Signposting you to specialist organisations.

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

Please contact us via telephone, email or LiveChat - 9am to 5pm, Monday to Friday (except English bank holidays).

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

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