Expert warns five pain-free signs of bowel cancer as cases rise in younger adults

A Bristol GP has warned that thousands could mistake subtle signs of bowel cancer for ordinary health issues as cases among people under 50 continue to rise. Dr. Jack Ogden told the Daily Mail that five 'silent', pain-free signals should be monitored closely to catch the disease early. The warning comes as experts note colorectal cancer—also called colon or bowel cancer—has surged by about 50 percent in younger adults over the past three decades, a trend recognized after the death of Dame Deborah James at age 40.

The first sign many patients overlook is iron-deficiency anemia, which can present as unexplained fatigue, pale skin or shortness of breath. Anemia occurs when tumors bleed in the bowel, depleting iron and triggering inflammation that interferes with iron absorption. Equally important, changes in bowel habits—constipation, diarrhea, or the appearance of narrower stools with no clear cause—can signal an issue. Pencil-thin stools, Dr. Ogden noted, may indicate an obstruction that funnels stool into a thinner shape.

Weight loss without deliberate dieting or exercise changes is identified as a third subtle sign, which can be gradual and not sudden. Metabolic demand from tumors, reduced appetite and nutrient malabsorption may contribute to this loss. Bloating and persistent abdominal discomfort can also appear as subtle signals, including cramping or feeling full quickly after meals. The fifth sign, blood in the stool, can be tricky: dark or hidden blood may require stool tests to detect, while bright red blood is more often linked to hemorrhoids.

Health guidance from the NHS notes that anyone experiencing these symptoms for three weeks or more should consult a GP. While most bowel cancer diagnoses occur in people over 50, rates in younger adults have risen by about 50 percent over the last 30 years. Cancer Research UK estimates that roughly 54 percent of UK bowel cancer cases are preventable, with risk factors including obesity, antibiotic over-use, and potential environmental triggers such as microplastics in drinking water. A recent global review found rising rates of colorectal cancer in 27 of 50 countries, with England among the places showing substantial increases: about 3.6 percent per year in younger adults. In the United States, the rate is climbing at roughly two percent annually.