Bowel Polyps: Understanding Abnormal Growth in the Colon and Rectum

Medically reviewed by John A. Flores M.D., M.S. April 11, 2024| Written by Abdul Jabbar

Bowel Polyps: Understanding Abnormal Growth in the Colon and Rectum

Abowel polyp or colorectal polyp is anabnormal growth (projection) from the inner lining of the gut into the lumen of the rectum or colon. Anyone can develop bowel polyps, but this condition becomes common as people age. Also, you’re at a higher risk if you’re a smoker or overweight.

Studies indicate that bowel polyps occur in almost30% of U.S. adults aged 50 or above. In other words, roughly1 in 4 people over 50 years develop at least one colorectal polyp. That said, bowel polyps also affect children who experience intestinal bleeding.

Typically, polyps grow on the left side of the rectum and colon.  most polyps are harmless, and only a few are potentially. 

This article will look closely at bowel polyps, their symptoms, causes, types, and treatment. We’ll also discuss lifestyle habits to prevent bowel polyps. Let’s begin!

How Serious is a Bowel Polyp?

Though a few bowel polyps are potentially cancerous, most of these arenon-cancerous (benign) and cause no issues. However, if left untreated for prolonged periods, these can cause harm. 

That said, colorectal cancer globally accounts for 10% of all major cancer cases. It’s also the 2nd leading cause of death related to cancer. More than one study confirms that colorectal cancer is prevalent in U.S. adults aged 65-74. 

 from NCI’s Surveillance, Epidemiology, and End Results Program (SEER)  from 2000 to 2014 reveals that each year, bowel cancer incidence increased by 2.7% among people aged 20-39 years, and about 1.7% among individuals aged 40-49 years.

They are somewhat more prevalent in the Western hemisphere. Therefore, healthcare providers promptly remove them when detected.

What are the Symptoms of Polyps in the Colon?

Most bowel polyps are asymptomatic, which means there are no apparent indicative symptoms. So, people usually only discover these after a colonoscopy. So, it’s essential to keep up with regular colon cancer screening.

However, bleeding from the rectum is one of the most commonly associated symptoms with bowel polyps. Though uncommon, some possible symptoms include

  • Sudden changes in bowel movements (i.e., constipation or diarrhea).
  • Iron deficiency anemia
  • Excess mucus
  • Crampy abdominal pain
  • Rectal bleeding
  • Blood in the stool

Please keep in mind that it's crucial to see a physician promptly if:

  • You’re constipated, and this hasn’t improved for a long time, even with treatment
  • You have lost a considerable amount of weight for unexplained reasons
  • Your bowel habits have starkly changed. 
  • You have blood or mucus in your poop for over three weeks.

TheNIH reports research has identified that your doctor may take a family and medical history first and then perform a thorough physical examination to decide which procedure or test is best suitable for you.

What are the Types of Polyps?

Healthcare providers divide bowel polyps in several ways. One such way is by examining the shape. 

However, using the fractional dimension is seen as a more straightforward, and effective way to measure the shape of the polyp, making it a valuable tool for distinguishing between different diagnostic categories.

A 2014 review concluded that bowel polyps of 5mm or less in diameter had a lesser risk of developing cancer compared to those ranging between 1.5cm to 3.5cm, with a potential risk of 19-43%.

Depending on the number, shape, and size, we classify these polyps into three main types, including:

1. Hyperplastic Polyps

This type of polyp has been considered harmless for decades. A  involving the link between colorectal cancer and hyperplastic polyps showed that there is not an increased risk of developing colorectal cancer. Also, these can be treated effectively without requiring surveillance colonoscopy.

Hyperplastic polyps can sometimes coexist with adenomatous polyps - potentially cancerous polyps.

So, even though hyperplastic polyps havelow malignancy potential, it would be a good idea to consult a physician for regular check-ups.

2. Adenomatous Polyps

Unlike hyperplastic polyps, adenomatous polyps have the potential to become cancerous, especially as they grow larger. That said, colorectal cancers candevelop from preexisting growths called adenomas, which are abnormal polyps found in the rectum and colon. 

So yes, these adenomas are considered dysplastic — meaning they have abnormal cell growth.

Although most adenomatous polyps remain non-cancerous, they can grow cancerous - especially in large adenomas. And so, it's crucial to remove these polyps to reduce the risk of colorectal cancer.

3. Malignant Polyps 

Malignant polyps, whether pedunculated or sessile, contain cancerous cells that can invade beyond the mucosa into the submucosa, even with the involvement of lymph nodes.

The best treatment for such polyps depends on the cancer severity and the patient’s overall health. 

It usually involves surgery to remove the polyp or any surrounding tissue that may be affected. Regular follow-up appointments are important after treatment to see any signs of recurrence.

However, malignant polyps are not ascommon as the other two types. 

Doctors typically identify these using a microscope where each type shows distinct morphologic features. After all, each polyp grows using a different process. 

The same procedure also helps determine if a bowel polyp is cancerous.  

What Causes Bowel Polyps?

Though it’s unclear exactly what causes bowel polyps; experts believe that these result from the body generating too many cells in the bowel lining - eventually leading to a bump called a polyp.

That said,certain factors increase the likelihood of developing bowel polyps:

If you’re already diagnosed with bowel polyps, you may be wondering: 

Can Intestinal Polyps Be Cured? 

Yes, you can completely recover from bowel polyps with proper treatment and care.

The standard treatment is just the removal of polyps as long as the said polyp isn’t cancerous. Typically, the approach for removal is by flexible sigmoidoscopy orcolonoscopy

However, this excision is only appropriate for non-cancerous polyps. So, once removed, these are tested for cancer. If found positive for cancer cells, further treatment depends on multiple factors, including cancer's extent and available treatments. 

That said, further studies and technological advancements are bringing more clarity to the treatment of cancerous bowel polyps as well as their preventive strategies. For instance:

  • Ananalysis of malignant extensive bowel polyps management found that endoscopic excision can be a sufficient treatment for malignant change unless the cancer has already spread to lymph nodes.
  • In the U.S., from 1975 – 2000, the colorectal incidence rates and deaths declined by 22-26%. The innovation of screening tests for colorectal cancer, such as the flexible sigmoidoscopy, colonoscopy, and fecal occult blood test, is credited for the decline.

TheNational Institutes of Health predicts that advanced screening accounts for a 50% drop in deaths caused by colorectal cancer. 

  • Research suggests that Ischaemic polypectomy with endo-clips at double-balloon enteroscopy may be a top-notch technique for managing small bowel polyps in patients with PJS (Peutz-Jeghers syndrome).
  • Precision endoscopy is a promising technique for early detection and excision of colorectal cancer and bowel polyps. Further imaging modalities in endoscopy may boost its optical performance.

That said,regular rectum and colon screening examinations can help in early detection and therefore, treatment of polyps. 

After treatment, the patient may be monitored for reoccurrence using simple blood tests. 

The Role of Lifestyle and Diet in Bowel Polyps

Though we cannot entirely prevent bowel polyps, specific measures may reduce the risk of developing them. According to theWorld Health Organization, several lifestyle considerations contribute to the chances of colorectal cancer, like processed meats, obesity, low intake of vegetables and fruits, smoking, and alcohol consumption.

So, based onresearch, it is apparent that the following changes in diet and lifestyle can do wonders:

  • Don’t smoke.
  • Get physical activity regularly.
  • Reduce alcohol consumption.
  • Maintain a healthy weight.
  • Reduce fat intake. 
  • Increase calcium and vitamin D intake.
  • Add lean meat and whole grains to your diet

Can Fiber Help With Bowel Polyps?

Yes, as fiber keeps things moving smoothly through the intestines. It reduces the chances of inflammation and irritation that may lead to polyps. 

Evidence shows that eating fiber-rich foods lowers your risk of developing bowel polyps. Fiber-rich foods include vegetables, beans, whole grains and fruits.

Asystematic review suggests that a high-fat diet can increase the number of polyps in people genetically prone to developing tumors.

Therefore, it is essential to stick to a balanced diet that is low in fat, but high in fiber to reduce the risk of recurring polyps. 


Statistics suggest that bowel polyps are common in adults residing in America — anywhere between15% to 40%. Such cases are even more common in older adults, especially men. The good news is that researchers found areduction in colorectal cancer mortality rates by 26% when sigmoidoscopy is included in the screening process. 

Therefore,  a fiber-rich diet with low lipid content can reduce the risk of developing bowel polyps. Once detected, a polyp is best treated by surgical removal. If a polyp is found to have cancer cells then further treatment may be crucial.

I hope this article helped you learn everything you need to know about Bowel Polyps.