A 27-year-old woman has shared the one obvious symptom doctors repeatedly dismissed before handing her a devestating stage four cancer diagnosis.

Rylie Toomey, of Mechanicsburg, Pennsylvania was living life the way most 20-somethings do, with her biggest concerns including the stresses of planning for her upcoming wedding and honeymoon, while also training for a half marathon.

Yet when she began to experience on-and-off pains in her stomach, Rylie knew that her body was trying to tell her something. As a result, she sought medical help, only to be told that she was suffering from constipation.

Weeks went by and her pain failed to subside. In fact – according to reports – it only worsened, until one episode back in April saw her crying out in pain while waiting for the emergency room.

Speaking to Today, she recalled: “In my head I was like, I think I’m going to die – that’s how much pain I was in. I felt like I was being stabbed, and my belly was super bloated, too. It felt like I was just going to explode.”

Sadly, Rylie’s strong suspicion that all was not well with her body proved to be entirely correct. She was eventually diagnosed with colon cancer – one of the fastest rising types of cancer in people below the age of 50 in the US.

Of her tragic diagnosis, Rylie said: “When you hear, ‘You have cancer,’ you’re just like, that can’t be right. That can’t be me because leading up to this, I was so healthy.

“To hear that I had colon cancer just didn’t make sense, just because you feel like colon cancer is linked to unhealthy people or people who eat unhealthy or the elderly. I just was not expecting that at all.”

As per the Mayo Clinic, colon cancer can have a genetic link, with certain inherited syndromes greatly increasing risk. The majority of colon cancers, however, appear to be caused by environmental and lifestyle factors, including diet, lack of regular exercise, obesity, smoking, and alcohol.

Given Rylie’s tender age and healthy lifestyle, her diagnosis came as even more of a shock. Indeed, the 27-year-old believes that may be why it took doctors so long to realize she had cancer.

“I felt like they weren’t looking too far into it. Just because I was so young, they weren’t going to do a colonoscopy,” she explained to Today.

“I didn’t feel like it was that urgent to them when it felt super urgent to me.”

In the aftermath of her diagnosis, Rylie has stressed the importance of “pushing for answers” when it comes to health, adding: “I just don’t want anybody to ever go through something like this. I think this happened for a reason so I can help others.”

For more on Rylie’s story, visit her fundraiser page here.