Colorectal cancer used to be considered a disease of the West. That has changed. Over the last two decades, the incidence of colon and rectal cancer in urban India has been rising steadily, and we are now seeing patients in their forties and even thirties walk into the clinic with advanced disease. The tragedy is that almost all of this is preventable, because colorectal cancer is one of the few cancers we can actually catch — and cure — before it becomes cancer at all. This guide explains why colorectal cancer screening in Chennai matters, what a colonoscopy involves, and who should get one.
Why Colorectal Cancer Is Rising in India
Several shifts in modern Indian life are working against our colons. Diets have moved away from high-fibre traditional meals toward processed foods, red meat, refined flour, and sugar. Office jobs and screen time mean most adults are far more sedentary than the previous generation. Obesity, diabetes, and smoking — all independent risk factors for colorectal cancer — are now common in our thirties and forties rather than our sixties. Cancer registries in Chennai, Mumbai, and Bengaluru have all recorded a clear upward trend in colon and rectal cancer over the last fifteen years.
The other problem is awareness. In India, cancer is still discussed in whispers, and bowel symptoms are particularly difficult for people to talk about even with their own doctor. As a result, many patients arrive at hospital only after months of bleeding, weight loss, or changing bowel habits — by which time the cancer has often spread.
Who Is at Higher Risk?
Some risk factors you cannot change. Others you can. Knowing where you stand helps you and your doctor decide when screening should begin.
- Age 45 and above — risk rises sharply with each decade thereafter
- A first-degree relative (parent, sibling, child) with colorectal cancer or large polyps
- A personal history of inflammatory bowel disease (Crohn’s disease or ulcerative colitis)
- A diet low in fibre and high in red or processed meat
- Obesity, type 2 diabetes, or metabolic syndrome
- Long-term smoking and heavy alcohol use
- Known genetic syndromes such as Lynch syndrome or familial adenomatous polyposis
If you have any of the inherited or IBD-related risk factors above, screening should begin much earlier — sometimes as young as twenty-five — and at shorter intervals. Your gastroenterologist can map out an individualised schedule.
Warning Symptoms You Should Never Ignore
Colorectal cancer in its early stages is often silent. By the time symptoms appear, the disease is usually past the easiest-to-treat phase. That is precisely why screening of asymptomatic adults is so valuable. Still, if any of the following appear, you should see a doctor without delay rather than waiting for your next screening interval: a noticeable change in bowel habit lasting more than a few weeks, blood in the stool (bright red or dark), the feeling of incomplete evacuation, unexplained weight loss, persistent abdominal cramping, or new-onset iron-deficiency anaemia. None of these symptoms automatically mean cancer — most are caused by piles, fissures, or other benign conditions — but they all deserve evaluation.
Why Colonoscopy Is the Gold Standard
There are several screening tests for colorectal cancer — stool-based tests, CT colonography, sigmoidoscopy — but colonoscopy stands apart for one reason: it is both diagnostic and therapeutic in the same sitting. During a colonoscopy, a thin flexible tube with a camera is passed through the entire length of the large intestine. If the doctor sees a polyp — a small growth that, given enough years, may eventually become cancer — it can be removed right then, while the patient is still on the table. No second procedure, no waiting, no spreading risk.
Most colorectal cancers arise from polyps that took five to ten years to develop. Removing a polyp during a routine colonoscopy is the closest thing in medicine to actually preventing a cancer from ever forming. This is why colonoscopy is recommended every ten years for average-risk individuals starting at age 45, and every three to five years if polyps are found.
What to Expect During the Procedure
A colonoscopy is a day-care procedure. The day before, the patient drinks a bowel-cleansing solution to empty the colon, which is the most uncomfortable part of the whole process — but it is what gives the camera a clear view. On the day, the procedure itself takes twenty to thirty minutes and is performed under light sedation, so most patients sleep through it and remember nothing. After about an hour of recovery, patients go home the same day. Normal activities can usually be resumed by the following morning.
Biopsies taken during the procedure are sent to the laboratory, and the doctor reviews the results with the patient at the follow-up visit. If polyps were removed, the histopathology report determines the timing of the next colonoscopy.
When Cancer Is Found Early, the Outcomes Are Excellent
The single most important predictor of outcome in colorectal cancer is the stage at diagnosis. Cancers caught in stage I — confined to the wall of the colon or rectum — have five-year survival rates above 90 percent. Treatment for early-stage disease is usually a single laparoscopic or robotic operation, often with no need for chemotherapy. Catching the same cancer at stage IV, after it has spread, brings survival figures down dramatically and turns the treatment into a much longer journey of chemotherapy, radiation, and multiple surgeries.
Modern colorectal surgery is now overwhelmingly minimally invasive. Laparoscopic and robotic techniques mean smaller incisions, faster recovery, and in the case of rectal cancer, a much better chance of preserving the anus and avoiding a permanent stoma. The surgeon’s training and experience in oncological technique — particularly total mesorectal excision for rectal cancer — directly influences the outcome.
What You Can Do This Year
If you are 45 or older and have never had a colonoscopy, schedule one. If you have a family history of colorectal cancer, do not wait until 45 — speak to a gastroenterologist about your personalised screening age. And if any of the warning symptoms above are present, treat them as a reason to consult now rather than later. Screening is the rare medical intervention that genuinely saves lives, and in colorectal cancer, the evidence is overwhelming.
Consult Dr. Gautham Krishnamurthy
Dr. Gautham Krishnamurthy is a fellowship-trained surgical gastroenterologist and GI oncology surgeon at P&G Hospital, Chennai. He performs diagnostic colonoscopy, laparoscopic and robotic colorectal cancer surgery, and offers individualised cancer screening plans.
For appointments, contact reception at P&G Hospital Chennai.