The symptoms of ulcerative colitis vary depending on how much of the rectum and colon is inflamed, and how severe the inflammation is.

The most common symptoms are:

• recurring diarrhoea, which may contain blood, mucus or pus
• abdominal (tummy) pain
• needing to empty your bowels frequently

You may also experience fatigue (extreme tiredness), loss of appetite and weight loss.

You may go for weeks or months with very mild or no symptoms (remission), followed by periods where the symptoms are particularly troublesome (known as flare-ups or relapses).

No specific trigger for flare-ups has been identified, although stress is thought to be a potential factor.

Additional symptoms

During a flare-up, some people with ulcerative colitis also experience symptoms not related to the inflammation in their bowels.

For example, some people develop painful and swollen joints (arthritis), mouth ulcers, areas of painful, red and swollen skin, or irritated and red eyes.

Symptoms of a severe flare-up

A severe flare-up is defined as having to empty your bowels six or more times a day, as well as having additional symptoms such as shortness of breath, a fast or irregular heartbeat, or a high temperature (fever).

You may also notice that any blood in your stools becomes much more obvious.

When to seek medical advice

You should see your GP if you have symptoms of ulcerative colitis and you haven't been diagnosed with the condition.

If you think you may be having a severe flare-up, contact your GP or care team (if you have already been diagnosed with ulcerative colitis) for advice. You may need to be admitted to hospital as a precaution.

If you cannot contact your GP or care team, call NHS 111 or contact your local out-of-hours service.

Acute

Acute means occuring suddenly or over a short period of time.

Dehydration

Dehydration is an excessive loss of fluids and minerals from the body.

Diarrhoea

Diarrhoea is the passing of frequent watery stools when you go to the toilet.

Fatigue

Fatigue is extreme tiredness and lack of energy.

Fever

A high temperature, also known as a fever, is when someone's body temperature goes above the normal 37C (98.6F).

Loss of appetite

Loss of appetite is when you do not feel hungry or want to eat.

Pain

Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.