Scientists enjoy warned people born around 1990 — are four times various likely to develop rectal tumours, which begin in the large intestine, approached to those born in about 1950.
They are also at twice the risk of colon excrescences, which start growing lower down.
Figures now show three in ten rectal cancer analyses are now in patients below the age of 55.
The study suggests people who reached adulthood primeval in the 21st century, are facing an epidemic — and suggests they may need screening from their prehistoric 20s.
The outlook is so bad that experts say the situation compares with the late 1800s.
Dr Rebecca Siegel, Epidemiologist, from the American Cancer Guild, Atlanta, said: «Trends in young people are a bellwether for the future plague burden.
«Our finding that colorectal (bowel) cancer risk for millennials has escalated again to the level of those born in the late 1800s is very sobering.
«Instructional campaigns are needed to alert clinicians and the general public about this dilate.
«We also need to encourage healthier eating and more active lifestyles to try to reverse this fad.»
In addition, her research team suggests the age to initiate screening people at middling risk may need to be reconsidered.
They point out in 2013 in the US, 10,400 new wrappers of colorectal cancer (CRC) were diagnosed in people in their 40s, with an additional 12,800 crates diagnosed in people in their early 50s.
Dr Siegel: «These numbers are alike resemble to the total number of cervical cancers diagnosed, for which we recommend telly for the 95 million women aged 21 to 65 years.»
In the UK, camouflage for bowel cancer is available to those over the age of 60.
Previous research has initiate snacking on chocolate, biscuits and cakes could increase the risk of the contagion, as could drinking fizzy drinks.
A diet high in red or processed meats, partiality bacon and sausages, and low in fibre increases the risk, as is being overweight or fat or being inactive.
A high alcohol intake and smoking has also been tied with the disease.
The study published in the Journal of the National Cancer Pioneer said the number of cases are rising in young and middle aged adults, covering people in their early 50s, with rectal cancer rates widening particularly fast.
Deborah Alsina, chief executive of Bowel Cancer UK, said: «This inviting study highlights the growing trend in colorectal cancer in under 50s in the US — the UK is finance a similar pattern.
«Every year in the UK, 2,540 people are diagnosed with colorectal cancer, a 45 per cent escalation over the last 10 years.
«It is interesting that there is a notably steep rise in the number of people under the age of 55 diagnosed with rctal cancer in America and experiment with has indicated a similar pattern in many countries around the world.
«This but research needs to be carried out in the UK to better understand current trends here.”
Bowel cancer MAPPED — butcher disease linked to DIET most common in THIS British precinct