The NHS is urging people to see their GP if they spot a warning sign that can appear anywhere on the body. Typically, it is found on the legs, and people are urged not to ignore it.

On its official website, the NHS highlights that "patches of painful, red, and swollen skin - usually on the legs" may indicate Crohn's disease. But what is it?

Crohn's disease is a lifelong condition with no known cure, triggered by inflammation within sections of the digestive system. It falls under the umbrella of inflammatory bowel disease(IBD), which encompasses various related conditions.

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What causes Crohn's disease?

The exact cause remains unclear, and there's no proof that any specific diet triggers Crohn's disease. Experts believe multiple factors may contribute, including:

• your genes – you're more likely to get it if a close family member has it


• a problem with the immune system (the body's defence against infection) that causes it to attack the digestive system


• smoking


• a previous stomach bug


• an abnormal balance of gut bacteria

What are the symptoms of Crohn's disease?

Anyone can get Crohn's disease, and symptoms usually start in childhood or early adulthood.

The main five symptoms are:

• diarrhoea – which may come on suddenly


• stomach aches and cramps – most often in the lower-right part of your tummy


• blood in your poo


• tiredness (fatigue)


• weight loss

You might not have all these symptoms but the NHS lists seven others. Some people with Crohn's disease also have:

• a high temperature


• feeling and being sick


• joint pains


• sore, red eyes


• patches of painful, red and swollen skin – usually on the legs


• mouth ulcers



• Children with Crohn's disease may grow more slowly than usual

It's noted that symptoms may be constant or they could come and go. When they reappear, experts call it a "flare-up."

The NHS website says: "There's currently no cure for Crohn's disease. But there are treatments that can help you stay without symptoms for long periods (in remission).

"The type of treatment you have will depend on your symptoms. You'll probably need different treatments over time.

"You'll be supported by a team of healthcare professionals including a specialist doctor (gastroenterologist). You'll have regular check-ups and tests."

Should I see my GP?

See a GP if you or your child have:

• blood in your poo


• diarrhoea for more than 7 days


• frequent stomach aches or cramps


• lost weight for no reason, or your child's not growing as fast as you'd expect

If your GP thinks you could have Crohn's disease, they will refer you to a gastroenterologist for tests to confirm the diagnosis.

Tests you may have include:

• a colonoscopy – a thin, flexible tube with a camera at the end is inserted into your bottom to look for inflammation in your bowel


• a biopsy – tiny pieces of your bowel are removed during a colonoscopy and checked for signs of Crohn's disease


• an MRI scan or CT scan – you may need to have a special drink first to make your bowel show up clearly on the scan