Weight loss, fatigue, anaemia? Watch out for subtle signs of colon cancer

Business Standard

a day ago

Colorectal cancer (CRC) is a common malignancy and a leading cause of death worldwide. In India, it ranks as the fourth most common cancer, according to a review published earlier this year in the Indian Journal of Gastroenterology.
However, its early signs are often subtle enough to be dismissed as minor digestive trouble. This tendency to ignore or misinterpret symptoms can delay diagnosis, sometimes until the disease is at an advanced stage.
Experts say that while men and women share many of the same warning signs, differences in tumour location, hormonal influence, and even attitudes towards health can lead to variation in how and when symptoms are recognised.
Symptoms people commonly overlook
"In the early stages, colon cancer rarely makes a dramatic entrance. Instead, it creeps in with mild changes that people often dismiss as harmless. By the time these clues are taken seriously, the disease can already be well advanced," said Dr SK Bala, onco-surgeon, Calcutta Medical Research Institute (CMRI).
According to Dr Bala, early symptoms are:
Sudden change in bowel habits – constipation, loose motions, or stools becoming unusually thin
Blood in the stool – bright red streaks or dark, tarry stools, often mistaken for piles
Unintentional weight loss – dropping kilos without trying, which some may wrongly see as a positive change.
Persistent abdominal discomfort – cramps, bloating, or pain that does not improve with over-the-counter remedies.
Unexplained tiredness or low haemoglobin levels - due to iron-deficiency, anaemia
Feeling of incomplete evacuation – the sense that the bowel hasn't fully emptied.
Gender differences in symptom presentation
While the basic symptoms are similar, the way colon cancer presents and how it's detected can vary between men and women.
"Men often delay seeking evaluation for rectal bleeding, attributing it to hemorrhoids, while women sometimes normalise fatigue or altered bowel patterns as menstrual-related changes or dietary causes. In clinical observation, women tend to present later when symptoms are vague, particularly when pain or bloating overlaps with gynaecological conditions," said Dr Satish Rao, surgical oncology, Lilavati Hospital Mumbai.
Talking about hormonal influence, he further said, "Oestrogen could have a protective function during colorectal carcinogenesis, which may in part account for reduced incidence in pre-menopausal women."
Discomfort or hesitation in discussing bowel symptoms adds another barrier to early detection. "Cultural perceptions and symptom interpretation differ between genders. Women may be more attuned to abdominal discomfort but less likely to report rectal bleeding, while men may underplay fatigue. These patterns can lead to diagnostic delays, particularly in cases without overt bleeding," Dr Rao said.
Why tumour location matters
The side of the colon where cancer develops influences both symptoms and treatment response.
Dr Bala explained, " Left-sided growths, being closer to the rectum, tend to cause symptoms people can see — fresh blood in stool, constipation, or altered bowel patterns, prompting earlier medical visits. Meanwhile right-sided tumours are trickier; they can grow larger without disturbing bowel habits, often causing only anaemia, general tiredness, or vague discomfort. As these signs are less obvious, they are easier to overlook."
The rising threat in younger adults
In recent years, colon cancer rates among people under 50 have risen sharply. This is particularly worrying because symptoms in younger adults are often dismissed by both patients and healthcare providers.
"A disturbing surge in early-onset colorectal cancer has been noted worldwide, with both males and females in their 20s and 30s being late-presenters. Female and male misperceptions that are gender-related delay diagnosis. The main reason of early onset colon cancer is both males and females is sedentary lifestyle, faulty dietary habits, alcohol and smoking," said Dr Rao
Younger patients face the added challenge that colon cancer is still seen as an older person's disease, leading to misdiagnosis or delayed investigation.
Lifestyle and risk factors
Dr Bala shared that certain habits and health conditions can increase colon cancer risk:
Diets high in red or processed meats and low in fibre
Sedentary lifestyle and obesity
Excessive alcohol consumption and smoking
Family history or genetic predisposition
Chronic inflammatory bowel diseases
Treatment and prevention
Experts say that early detection remains the most powerful tool against colon cancer.
Screening: Colonoscopy from age 45 for those at average risk; earlier for high-risk groups.
Lifestyle adjustments: A fibre-rich diet, reduced red meat, quitting smoking, alcohol abstinence and regular exercise.
Medical interventions: Removing pre-cancerous polyps during colonoscopy, targeted therapies, and in some cases, immunotherapy.
"Colonoscopies can spot and remove polyps before they become cancerous, with most guidelines suggesting screening from age 50- or 45 for some. When caught early, surgery (sometimes paired with chemotherapy or radiation) can be curative. Robotic-assisted techniques are increasingly used, offering greater precision and quicker recovery," said Dr Bala