The Link Between Diabetes and Colon Cancer

Written by Dr. Bharat Pothuri, MD, FACG | Updated On 07-28-2025

The Link Between Diabetes and Colon Cancer

What You Need to Know

Welcome to Gastrodoxs! Today we're looking at an important topic: the connection between diabetes and colon cancer.

If you've ever asked:

• Does diabetes increase colon cancer risk?
• How does diabetes affect colon health?
• What's the risk of colon cancer in type 2 diabetics?

You're in the right place. We'll explain it all—with help from Houston-based GI expert Dr. Bharat Pothuri.

Section 1: Quick Look at Diabetes

Diabetes happens when your body can't manage blood sugar properly. There are two main types:

• Type 1 – Your body doesn't make insulin.
• Type 2 – Your body doesn't use insulin well.

Most adults have type 2 diabetes. Over time, high blood sugar can harm organs, nerves, and blood vessels.

“Diabetes isn't just about sugar,” says Dr. Pothuri. “It affects many parts of the body, including the colon.”

Fast facts:

• Over 34 million people in the U.S. have diabetes.
• Type 2 is linked to age, weight, and lack of activity.
• Early diagnosis helps avoid long-term problems.

Section 2: What Is Colon Cancer?

Colon cancer, also known as colorectal cancer, starts in the large intestine or rectum. It often begins as small growths (polyps) that can turn into cancer over time.

Key points:

• Warning signs: blood in stool, changes in bathroom habits, belly pain
• Screening tip: colonoscopy every 10 years, or more often if needed
• Good news: early detection leads to a 90% five-year survival rate

Learn more: CDC Colon Cancer Screening Guide

Section 3: Does Diabetes Raise Colon Cancer Risk?

Studies show that people with type 2 diabetes have a 20–30% higher chance of getting colon cancer.

Why?

• Insulin resistance – High insulin can fuel tumor growth.
• Chronic inflammation – Ongoing inflammation can damage cells.
• High blood sugar – Glucose may help cancer cells grow.

“Diabetes doesn't mean you'll get colon cancer,” says Dr. Pothuri. “But it raises your risk—so screening matters.”

Section 4: How Diabetes and Colon Cancer Are Linked

Here's a simple breakdown of the diabetes and colorectal cancer connection:

• High insulin and IGF-1 – These hormones may help cancer cells grow faster.
• Oxidative stress – High blood sugar creates harmful molecules that damage DNA.
• Chronic inflammation – Long-term inflammation is common in type 2 diabetes.
• Gut bacteria changes – Diabetes may affect your gut's natural balance.

Summary: How Diabetes Impacts Risk

• More insulin and growth hormones
• Damage to cells from sugar spikes
• Ongoing inflammation in colon tissue
• Disrupted gut microbiome

Learn more at NIH – Diabetes and Cancer

Section 5: How Diabetes Affects Your Colon

Diabetes can affect colon health in several ways:

• Slow digestion – Food and waste move more slowly, which may irritate the colon lining.
• Unhealthy diets – High-sugar foods hurt more than just blood sugar—they can damage cells.
• Weak immune defenses – Poor sugar control makes it harder to fight off abnormal cells.

“In Houston's hot weather, people struggle to stay on healthy diets,” says Dr. Pothuri. “We help create plans that support both blood sugar and colon health.”

Section 6: Colon Cancer Risk in Type 2 Diabetics

• 20–30% increased risk of colon cancer
• Higher risk for right-sided colon cancer
• Men may face slightly more risk than women
• The good news? You can lower this risk with the right steps.

Section 7: Dr. Pothuri's Advice for Patients

“If you have diabetes, don't skip your screenings,” says Dr. Pothuri.

“We often begin colonoscopies earlier for patients with type 2 diabetes.”

“Healthy weight, good food, regular movement, and stable sugar levels go a long way.”

“Houston has amazing resources—just ask your local Gastrodoxs team for help.”

Section 8: Healthy Habits That Lower Risk

Good habits can protect you from both colon cancer and diabetes problems.

Smart Lifestyle Choices:

• Keep a healthy weight
• Eat more fiber and less red meat
• Exercise at least 150 minutes each week
• Avoid smoking and limit alcohol
• Keep your blood sugar in check

Screening Musts:

• Colonoscopy every 10 years (or every 5 if polyps are found)
• Ask your doctor about stool tests
• Share your family history with your provider

Tip: The Houston Gastroenterology Center offers walk-in screenings and workshops on sugar control.

Section 9: Risk Comparison Table

Section 10: Final Thoughts

Diabetes and colon cancer are connected—but the risks aren't set in stone.
If you have type 2 diabetes, you may face a higher risk. But with regular screenings, better food choices, exercise, and blood sugar control, you can take charge of your health.
At Gastrodoxs, Dr. Bharat Pothuri and our Houston team are here to help. Let's build a plan that works for you.

External Resources

• CDC – Colon Cancer Screening
• NIH – Diabetes and Cancer

Thank you for reading!

Please share this post with friends and family in Houston and beyond. By learning more about the diabetes and colon cancer connection, we can take steps to stay healthy—together.

About the Author

Dr. Bharat Pothuri is a Board-Certified Gastroenterologist and Hepatologist. With extensive experience in digestive health, he specializes in advanced endoscopic procedures, chronic GI disorder management, and preventive care. Dr. Pothuri is dedicated to providing expert, patient-focused insights to help improve gut health and overall well-being.