Colon cancer is on the rise, particularly among younger adults under the age of 50, due to a combination of factors including lifestyle, environmental influences, and changes in gut bacteria. There is no single known cause, but likely contributors include obesity, Western-style diets high in processed foods and red meat, sedentary lifestyles, smoking, excessive alcohol use, and exposure to microplastics. Additionally, recent research highlights the role of gut bacteria, specifically strains of E. coli that produce a DNA-damaging toxin called colibactin, which may set the stage for colon cancer developing decades later. This bacterial factor, along with other environmental and lifestyle variables, is suspected of promoting mutations that lead to early- onset colorectal cancer. Further, despite the increase in cases among younger people, most colon cancer diagnoses still occur in those over 50. The rise in younger individuals is concerning because these cancers are often diagnosed at a later, more aggressive stage. Changes in screening guidelines to begin screening at age 45 may partially explain more diagnoses but do not fully account for the long-term rising trend observed since the mid-1990s. In summary, rising colon cancer rates appear linked to complex interactions among genetics, lifestyle factors like diet and exercise, environmental exposures, and shifts in the gut microbiome starting early in life, creating a perfect storm for increased risk in younger populations.