Ulcerative colitis is a chronic inflammatory bowel disease that causes the lining of the large intestine and rectum to swell and develop sores. Symptoms typically worsen during a flare-up.

Most people with ulcerative colitis (UC) have periods of active symptoms, and these are known as flares, or flare-ups. They are followed by periods when the symptoms disappear, called remission.

The most important part of treatment for UC is managing and easing the symptoms and increasing the length of remissions.

Diet plays a part in managing ulcerative colitis flare upsShare on Pinterest
David Malan/Getty Images

The exact causes of UC and its flares are still unknown. Researchers have ruled out diet and stress as primary factors.

However, stress may trigger flares, and a key element of preventing or easing flares involves making dietary changes.

Now, researchers believe that an overreaction of the immune system is the most likely cause of UC and that a family history can be a predictor of who will develop it.

UC is a type of inflammatory bowel disease that affects the lower parts of the digestive tract. It usually starts in the rectum, moves to the anus, and may eventually move to other parts of the colon.

A variety of symptoms can characterize UC, and the combination and severity can vary from person to person.

UC symptoms during a flare include:

Certain foods and drinks can also make UC symptoms worse. It is important to note which foods and drinks can trigger or worsen symptoms and to avoid them, especially during flares.

A large part of treating UC involves preventing and controlling flares.
This can require different approaches for different people. Below, find some strategies that often help:

Diet plans

A diet plan can be crucial to preventing and managing flares.

It might involve having a list of foods and drinks that do not trigger symptoms or a full meal plan that incorporates them. A doctor or dietitian can help recommend options and improve the healthfulness of a plan.

To identify safe and triggering foods, it can help to keep a journal that tracks meals and any symptoms.


Managing stress is an important part of a UC prevention plan, as stress may trigger flares.

Among the many ways to manage stress levels are exercise, therapy, and relaxation techniques or relaxing activities.


A doctor can prescribe a variety of medications to treat bowel inflammation. Current guidelines recommend long-term treatment with one of the following types of drugs.

These medications can help prevent flares by changing how the immune system works:

  • TNF-α antagonists, such as infliximab (Remicade) or adalimumab (Humira)
  • anti-integrin agents, such as vedolizumab (Entyvio)
  • Janus kinase inhibitors, such as tofacitinib (Xeljanz)
  • interleukin 12/23 antagonists, such as ustekinumab (Stelara)
  • immunomodulators, which may be methotrexate or a type of thiopurine, such as azathioprine

5-aminosalicylic acid

Historically, 5-aminosalicylic acid, or 5-ASA, has been a key treatment option for UC. A person can take it in pill form or as suppositories to reduce inflammation.

Examples include mesalamine (Azacol), balsalazide (Giazo), and sulfasalazine (Azulfidine).

Doctors can also prescribe a sulfa-free form of the drug for people who are allergic to sulfa.


Newer treatment options aim to reduce the need for steroid use.

Steroids have an anti-inflammatory effect, but doctors only prescribe them for short-term use, if other medications are not working. They are not a first-line choice because they can cause side effects and long-term complications.

The doctor will work with the individual to make a treatment plan that suits them best.


A doctor may suggest surgery if dietary changes and medications are not working or further complications have developed.

While surgery is usually a last resort, several options can help:

  • Removing the colon, rectum, and anus. After removing these organs, the surgeon makes an opening in the abdomen and passes part of the small intestine through the opening, forming a stoma. The person will wear a detachable ostomy bag over the stoma to collect their waste.
  • Removing only part of the lower tract. After this surgery, a person can have bowel movements as before, but they may still experience UC.
  • Creating a new rectum from the small intestine. The surgeon then attaches this to the anus. The person can still use the bathroom, but they need to wear a bag initially, as the new rectum heals. They may still experience UC.

See a doctor about any UC symptoms that spark concern. Persistent diarrhea lasting longer than 48 hours, for example, signifies something more serious than a minor flare-up.

As the symptoms of UC are often similar to those of other chronic bowel diseases, such as irritable bowel disease, the doctor will need to rule out similar illnesses.

To reach a diagnosis, a doctor looks at the person’s family history, their symptoms, and the results of a physical exam and, sometimes, a colonoscopy.

A colonoscopy involves examining the inside of the colon using a thin, flexible tube with a camera attached.

After diagnosing UC, the doctor gives a clear plan of action, outlining what steps to take when symptoms flare up. They also provide information about managing UC, including common triggers to avoid.

When a person experiences a flare, they do not necessarily need to see a doctor, as long as a management plan is in place.

The plan should include:

  • a list of safe foods
  • a list of foods to avoid
  • safe medications to take to manage pain, nausea, and diarrhea
  • when to call the doctor

When a person experiences a UC flare, they also should continue their prescribed treatment.

If following a flare management plan is not helping, or if symptoms are worse than usual, contact a healthcare provider.

Here are some questions people often ask about a colitis flare-up.

What does a colitis flare feel like?

A person experiencing a colitis flare up will notice an onset of symptoms such as abdominal pain, diarrhea, and urgent, painful bowel movements.

How long does a colitis flare-up last?

There is no typical time for a colitis flare-up to last. The two stages are remission and flare-up. How long it lasts will depend on the individual. Treatment may also help shorten or reduce the impact of a flare-up.

How do you calm a colitis flare-up?

Ways of calming a colitis flare include:

  • avoiding foods known to trigger a flare
  • managing stress
  • speaking with a doctor about the treatment plan, which may need adjusting

Some functional foods, such as curcumin (present in turmeric) and certain probiotics, may help achieve remission, although more research is needed. Another possible option is a fecal microbiota transplant, although this, too, is still experimental.

What triggers colitis attacks?

It is not always clear what triggers a colitis flare, but some factors include:

  • not taking medication according to the treatment plan
  • certain dietary choices
  • stress

A colitis flare is when symptoms reappear after remission. A person may notice an increase in abdominal pain, diarrhea, and the need to pass stool urgently. There may also be blood in stool.

A flare may occur if a person experiences stress, if they eat trigger foods, or if they are unable to follow their treatment plan.

To manage a flare, it is essential to speak with a doctor, who may need to adjust the treatment plan. They may also advise on dietary changes or ways to manage stress.

Read this article in Spanish.