When Ellie Wilcock was hit by sharp pains on one side of her abdomen and sudden bouts of fatigue in 2022, she blamed it on a urinary tract infection. 

But the actual cause was a cancer that kills almost 17,000 Brits each year — and is climbing in the under 50s.

The then 25-year-old from Peterborough was diagnosed with stage four bowel cancer – the most serious kind of the disease that means it's spread elsewhere in the body.

Now in a TikTok video, seen over 400,000 times, she has warned of the four early warning signs she suffered before her diagnosis. 

Perhaps the most unusual was am agonising pain that affected just one side of her abdomen and pelvis, leading some doctors to believe there was a problem affecting her reproductive system.

'It [the pain] was in my left hand side,' she said. 'It was because the tumour was obstructing my large bowel. 

'I thought it was more like urinary pain...doctors thought it was a UTI.'

 In another clip, she explained that some hospital doctors believed she may be suffering an ovarian cyst.

 Ms Wilcock also suffered other symptoms that are more commonly associated with bowel cancer. 

The first, a change in bowel habits that saw her experience both diarrhoea and constipation.

She said: 'For me, it was a constant change between the two but it just wasn't normal for me'

'And fatigue. I would come home from work and just want to lie down and go to bed. 

'I was really tired, I was really fatigued. Even sat at my desk, I was falling asleep I was so tired.'

She also noticed blood in her stool; another well recognised sign of the condition.

'At the time I didn't think I had this but on reflection I did and just didn't notice it,' she said. 

'This could be a range of colours, it could be bright red or a dark red. 

'But anything that isn't normal for you and you've noticed consistent blood in your poo then get it checked out.

'It is nothing to be embarrassed about. The sooner you look at it, the sooner you get it out the way.'

According to the NHS, anyone experiencing these symptoms for three weeks or more is advised to speak to their GP.

Bowel cancer symptoms can also be caused by other conditions like irritable bowel syndrome, but it's important to get checked so the disease can be spotted as early as possible.

Ms Wilcock first sought help for the pain in her abdomen in April 2022.  

Tests for a UTI came back negative, but blood tests conducted around the same time showed markers of inflammation. 

Such signs can indicate cancer but also other potential diseases and conditions. 

She was then booked in for an ultrasound, and doctors expected to find an ovarian cyst.

 But the pain worsened rapidly, forcing her to seek aid via A&E. 

It was only when a biopsy was conducted that the devastating truth was revealed.

Tests in February 2022 revealed the disease had spread to her liver, ovaries and the peritoneum – the membrane that holds the organs in the abdomen. 

After undergoing multiple surgeries to remove her cancer as well as gruelling rounds of chemotherapy, in August 2022 she was told there was no more evidence of the disease. 

In her fresh TikTok video she urged anyone experiencing unusual symptoms to get checked out straight away.  

'I always say cancer can happen to anyone, it doesn't discriminate.

'It is just a bulldozer that moves into people's lives and it fills waiting rooms with people, all with their own stories, their own families fighting this horrible disease.' 

Her post comes as experts continue to warn of a disturbing rise in bowel cancers in under 50s, which has baffled doctors around the globe.

The disease, the third most common cancer in the UK, is the same type that killed Dame Deborah James at age 40 in 2022. 

There are more than 44,000 new bowel cancer diagnoses in the UK each year, and almost 142,000 in the US. 

Although the vast majority affect those aged over 50, rates in older age-groups has either declined or held stable while diagnoses in younger adults have risen by 50 per cent over the last 30 years.

Earlier this month, actor James Van Der Beek revealed he has been diagnosed at the age of just 47.

Cancer Research UK estimates that over half (54 per cent) of bowel cancer cases in the UK are preventable. 

Doctors have suggested obesity, antibiotic over-use, mobile phone radiation and even invisible particles of plastic in drinking water are potential triggers. 

However a growing number of experts are pointing ultra-processed foods as a cause.  

Also known as UPFs, these are ready-made foods — including bread, cereals and even salad dressing — made with artificial ingredients used to preserve, add flavour and enhance texture.

Some have even gone as far as to say they could be as dangerous as tobacco — and should come with a cigarette-style health warning.

Speaking to MailOnline earlier this year oncologist and Queen's University Belfast professor Dr Joe O'Sullivan said: 'The spike in young cancer rates has to be due to something we're consuming.

'And ultra-processed foods are the biggest lifestyle change in the last 40 years.'

A further concern is that younger people with colorectal cancer suffer slightly different symptoms from older patients, according to a recent study.

The researchers looked at 5,000 people in Taiwan of various ages with the disease, found six in 10 under-50s suffered rectal bleeding before being diagnosed with the disease, compared to fewer than half of over-50s.

And nearly 60 per cent of young people with the disease also experienced changes in their toilet habits in the lead up to or after a diagnosis, compared to 48 percent of older patients.

The study found patients under 50 are more likely to be diagnosed later when the cancer had spread, perhaps because they dismiss the health changes.