When Victoria Collins found herself being forced to lie down last June because she was so bloated after dinner, she knew that something was wrong.

The adult support care worker from Hamilton, near Glasgow, had never experienced anything like it.

But the then-39-year-old simply thought it was a reaction to the meal she had just eaten.

Blaming it on a sudden food intolerance or irritable bowel syndrome (IBS) – a digestive issue which, while unpleasant for sufferers, is not life-threatening – she began cutting out everyday ingredients, and before long she was convinced she’d uncovered the cause. Onions.

‘When I’d make a curry, I’d always add extra onions purely because I love them. Yet suddenly my stomach became really sore,’ says the mother of three.

‘On one occasion, after making a pasta bolognese with plenty of garlic and onions, I had to go and lie down immediately because my stomach was so bloated.

‘The more “good” or “healthy” food I was eating, the more I was suffering. It wasn’t just bloating, there were cramps, lower back pain, constipation.

‘But I was still convinced it was IBS or the allergy, and tried to ride it out.’

Victoria Collins, who was diagnosed with stage three bowel cancer, with one of her daughters

It was only three months later, in early autumn 2024, when she noticed ‘really dark, really thick’ blood in her stools that alarm bells began to ring.

Left with no choice but to pluck up the courage and visit a doctor, she was immediately referred for blood and stool tests.

Weeks later after scans and a biopsy, the cause of her myriad health issues was revealed. Victoria, now 40, had stage three bowel cancer. It had already begun to spread through her body, meaning she was at high risk.

Since her diagnosis in November she has undergone surgery to remove the cancerous lymph nodes and tumour, as well as five rounds of chemotherapy.

‘It’s just so overwhelming – I was in a very dark, lonely place. You’re in a total state of shock initially,’ she says.

‘I was living a normal, healthy life which was completely flipped upside down. I didn’t ask to be living a nightmare but I was and I had no choice but to face it head on.’

Every year, 44,000 Britons are told they have bowel cancer. And while overall rates are stable, or have declined slightly in older age groups, cases among younger adults, or under-50s, are rising.

Indeed, research shows those born in 1990 are nearly two-and-a-half times more likely to get bowel cancer than someone born in 1950.

These early-onset cases are also more likely to be diagnosed at a later stage, once it has spread.

Dame Deborah James was one well-known example, diagnosed in 2016 at the age of just 35, after initially being told her symptoms were likely due to IBS or stress.

The podcaster and campaigner, who used her social media profile ‘Bowel Babe’ to spread awareness of the disease, died from it, aged 40, in 2022.

But the reason for later diagnoses is two-fold, experts say.

‘The idea that bowel cancer is a disease of older individuals is still dominating the decision making in some GP practices,’ says Dr Marco Gerlinger, a gastrointestinal cancer medicine professor and consultant oncologist at Queen Mary, University of London.

‘The increasing number of young patients with a bowel cancer diagnosis is clearly noticeable in our clinics.

‘So many tell me they’ve had multiple appointments over six to nine months before bowel cancer was ever really considered. And, of course, often they don’t usually think at first that they’re at risk of a cancer diagnosis – IBS is far more common than cancer – but self-diagnosing carries such a risk.’

Professor Sir Neil Mortensen, chairman of the Oxford Colon Cancer Trust and a leading bowel cancer expert, says: ‘Health professionals and public still see colon cancer as a problem for 70-year-olds.

‘Such symptoms are so easily overlooked, which means we’re seeing far more cases present as stage two or three.’

Currently adults aged 50 to 74 in England are offered a free at-home bowel cancer test every two years.

But with more than 2,600 people diagnosed each year before they reach screening age, experts have called for better earlier detection of the disease.

Researchers too are scrambling to uncover exactly what is behind the surge in younger people being diagnosed.

‘Although it is sometimes attributed to lifestyle factors such as diet, ultra-processed foods or obesity, they are not enough to explain this increase,’ says Dr Kevin Monahan, a consultant gastroenterologist at St Mark’s Hospital in north-west London.

‘National screening is not available for under-50s, and may not be the right approach. It’s vital that we develop a strategy sooner rather than later.’

For Victoria, the side effects of the treatment have been minimal.

‘I feel so lucky they were able to catch it in time,’ she says.

‘In April, the hospital said they had removed the cancer, and I had another final round of chemotherapy, which I’ve just finished.

‘Now it’s a waiting game for my final results in August.

But I know, given my age and how advanced the cancer was, I will always be at high risk of recurrence. This is something I just have to live with.’