A new study has found an increased risk of colorectal cancer among millennials.

According to the recent study published by the American Cancer Society, people born around the year 1990 are two times more likely to develop colon cancer and four times more likely to develop rectal cancer, when compared to their parents' generation at the same age.

While doctors have a sneaking suspicion, they say they still aren't absolutely certain what the cause is.

Jovannie Lorenzo of New Jersey was diagnosed with colon cancer at age 31. "It's considered to be an older man's disease. Well, I think I'm here to tell you otherwise," says Lorenzo.

Doctors like Victoria Gomez at the Mayo Clinic in Jacksonville haven't quite pinpointed the cause just yet, but she believes it may have to do with poor diet: not enough fruits, too much red and processed meat, and not enough exercise.

"The thought is that these risk factors may be the cause of these rising rates in colorectal cancer in millennials," says Gomez. He says the large number of young people with dietary issues has to do with how our society now takes in such high calories, diets high in carbohydrates and low in fiber. It all sets up for what she calls a metabolic disaster.

"I think a lot of it has to do with lifestyle behavior and our society as a whole. I mean, look around you at what people are serving at schools," she said.

Jacksonville dietician Holly Pudwill says it's about finding time to prepare healthy foods and getting 150 minutes of exercise in per week.

"Time is much more crunched now-a-days, and so people are just reaching for convenience foods now, with both people in the household working, we don't have that gatekeeper to the food home preparing complete meals anymore," said Pudwill.

Colorectal cancer symptoms include loss of appetite, weight loss and bloody stool, but many do not have symptoms.

As of now, Dr. Gomez said there are no guidelines to screen people in their 20s and 30s for colorectal cancer.

Could that change? While diet and exercise may indeed be to blame, she said more research needs to be done to find the exact cause of colorectal cancer in young people.