Find a Surgeon

 Obesity and Its Effects on the Colon

It stands to reason that excess weight and obesity would affect the large intestine or colon. After all, what we eat directly affects the GI tract, and colon health is directly related to overall health. Further, as obesity in the United States has become more prevalent, the incidence and severity of colon cancers and rectal cancers have increased as well.

Studies have shown that those suffering from obesity have an approximately 30-70% greater likelihood of developing colorectal cancer. This risk is higher in men than in women, but both genders show increased risk.1 Why the increase in colorectal cancer? We know that several risks for cancer in various parts of the body are heightened by obesity – the colon and rectum are no different. One mechanism by which cancer could proliferate may be caused by hormonal changes due to chemicals secreted by the fat. Cancer may also be more likely to occur because of the changes to the gut microbiome that overweight and obese patients experience.

A very comprehensive study has also shown increases in the risk of diverticulitis and diverticular bleeding particularly because of obesity. Over 47,000 male health professionals with no diverticular disease in 1986 were followed with waist and hip circumference data collected. The higher BMI, greater waist and hip circumference and the higher waist to hip ratio increased the risk of diverticulitis significantly.2

Obesity can also complicate the progression and treatment of these diseases. Obesity related inflammation in the body can worsen colorectal disease. Further, excess weight and obesity can increase the perioperative and postoperative risk for patients undergoing any kind of surgery, including colorectal procedures.

Of course, prevention is key and losing weight through improved diet and exercise can do wonders for reducing the risk of a multitude of colorectal disorders. Bariatric surgery may also benefit some patients suffering from morbid obesity and obesity related diseases. Patients considering bariatric surgery can find a bariatric surgeon in their area using our website.

Regardless, knowing these facts, it becomes critically important to start a colorectal cancer screening regimen in the form of colonoscopy.


1Bardou M, Barkun AN, Martel M. Obesity and colorectal cancer. Gut. 2013 Jun;62(6):933-47. doi: 10.1136/gutjnl-2013-304701. Epub 2013 Mar 12. PMID: 23481261.

2Strate LL, Liu YL, Aldoori WH, Syngal S, Giovannucci EL. Obesity increases the risks of diverticulitis and diverticular bleeding. Gastroenterology. 2009 Jan;136(1):115-122.e1. doi: 10.1053/j.gastro.2008.09.025. Epub 2008 Sep 25. PMID: 18996378; PMCID: PMC2643271.

List Your Practice

Surgeons, practitioners, and hospitals wishing to be included in the Bariatric Surgery Corner directory can do so by submitting their listing to us.