Colon Polyps

What is Colon Polyps?

Colon polyps are lumps that can grow in the colon, usually randomly, or as part of different medical conditions. Polyps can be sorted by size: if they are 5 millimeters or less in diameter, they’re called diminutive; if 6 to 9 millimeters, they’re small; or if 1 centimeter or more, they’re large. Polyps can have different shapes: they can be flat, have a broad base, or hang like a mushroom from a stalk. Some polyps develop from a layer of tissue under the mucosa – examples are lipomas, carcinoid tumors, or groupings of immune system cells. The majority of polyps form from the mucosa, the innermost layer of the intestine, and can be adenomatous (tubular, villous, or tubulovillous), serrated, or non-cancerous (hyperplastic and juvenile). Hyperplastic polyps are very common and have a very low risk of becoming malignant. They are usually located in the part of the colon that is closer to the rectum. Juvenile polyps are benign lumps that are common in children.

What Causes Colon Polyps?

Several things can increase your risk of developing colon polyps. These risk factors include getting older, being male, following a diet that’s high in fat and low in fiber, using tobacco, and drinking more than eight alcoholic drinks a week. People who have relatives with polyps, colorectal cancer, or a condition called intestinal polyposis also have a higher risk. On the other hand, having inflammatory bowel disease appears to lower the chance of having polyps.

Risk Factors and Frequency for Colon Polyps

Colorectal polyps, also known as growths in the lower part of the digestive system, become more common as people age. They are particularly frequent in western countries. In the United States, these polyps affect about 30% of people over 50 years old. Surprisingly, they also impact around 6% of children, a figure that can double to 12% in kids who have lower gastrointestinal bleeding. These polyps are most commonly found in non-white men.

Signs and Symptoms of Colon Polyps

Polyps are typically silent and are often discovered during routine colonoscopies conducted to check for colorectal cancer. However, in certain instances, individuals may present with painless rectal bleeding of bright or dark red color. This bleeding may be noticeable when wiping or mixed with bowel movements. Other possible indicators of polyps can include diarrhea, constipation, abdominal pain, mucus with stools, or symptoms associated with iron deficiency anemia due to ongoing bleeding. A physical examination usually doesn’t reveal anything abnormal, though polyps may be felt during a manual rectal examination or if they are sticking out of the rectum. A fecal occult blood test (FOBT) performed during a manual rectal exam is not as effective as an FOBT performed on naturally passed stool.

• Painless rectal bleeding (bright or dark red color)
• Diarrhea
• Constipation
• Abdominal pain
• Mucus with stools
• Symptoms linked to iron deficiency anemia from chronic bleeding

Testing for Colon Polyps

The first tests doctors usually run when they suspect a problem include a Complete Blood Count (CBC) to check for anemia, which can result from long-term bleeding, and a Basic Metabolic Panel (BMP) to look for any imbalances in the body’s essential chemicals or electrolytes. Some types of adenomas, or tumors, that produce excess hormones can cause these imbalances.

Next, a stool test may be ordered to detect the presence of blood. There are a couple of different types of these tests. The guaiac-based fecal occult blood test (gFOBT) changes color if blood is present in the stool. The fecal immunochemical test (FIT) or Immunochemical Fecal Occult Blood Test (iFOBT) uses antibodies specifically designed to react to human hemoglobin, a protein in red blood cells. A Stool DNA test is also available, which is more sensitive but less specific than the FIT.

The most definitive way to detect polyps, which are abnormal growths in the colon, is a procedure called a colonoscopy. During this procedure, a long, flexible tube with a small camera on the end is inserted into the colon, and any polyps found can be removed and examined as part of the procedure. However, colonoscopy is not a perfect screening method as it could miss some smaller polyps, especially if the bowel preparation is not optimal, the polyps are located on the right side of the colon, or the doctor performing the procedure is less experienced. If more than ten colorectal adenomas are found, further testing for specific genetic mutations (MUTYH and APC) should be carried out.

An alternative screening method is a computed tomographic colonography (CTC). This is similar to a colonoscopy, but uses X-ray imaging to create a detailed picture of the colon. It requires excellent bowel preparation, and may be less effective in identifying flat polyps. Other diagnostic methods include double-contrast barium enemas and colon capsule endoscopies.

There are also ongoing developments in the field of advanced optical technologies that may help to distinguish between cancerous and non-cancerous colon polyps. These include narrowed spectrum endoscopy, narrow-band imaging (NBI), confocal laser endomicroscopy (CLE), Fujinon intelligent color endoscopy (FICE), and image-enhanced endoscopy (i-scan).

Treatment Options for Colon Polyps

Colonic polypectomy is a procedure performed during a colonoscopy to either diagnose or treat certain conditions. It involves the removal of polyps from the colon. With pedunculated (stalk-like) polyps, a technique called snare polypectomy with electrocautery is used, while sessile (flat) polyps are treated with mucosal resection.

In certain situations, a total colectomy, which involves removing the entire colon, may be performed. This is usually done for preventative reasons, in conditions like Familial Adenomatous Polyposis (FAP) and MUTYH-associated polyposis (MAP), or when there is persistent bleeding or too many polyps.

Guidelines suggest that people generally should start getting colonoscopies for Colorectal Cancer (CRC) screening at 50 years old, or earlier if they are at a higher risk. Screenings usually stop when the person’s life expectancy is less than 10 years.

Certain factors can increase the risk of developing colon cancer. These include the type and size of polyps, their location in the colon, and having more than three polyps. Depending on these factors, the recommended timeline for a follow-up colonoscopy can vary from 10 years to less than 3 years.

Additionally, if the removed polyps show concerning features that suggest a high risk of cancer (like invading the lower third of the submucosa, unclear or positive resection margins, being less than 1 mm from the margin, lymphovascular invasion, or poor differentiation), a colectomy might be recommended due to the high likelihood of lymph node metastasis.

What else can Colon Polyps be?

• Pseudopolyps, which are irregular growths in the colon
• Juvenile polyposis, a condition where polyps develop in the digestive tract during childhood
• Hyperplastic polyposis, a condition where multiple harmless polyps form in the colon
• Familial polyposis coli, a genetic disease causing numerous polyps to grow in the large intestine
• Turcot syndrome, a rare genetic condition that leads to the growth of polyps in the colon and increases the risk of brain tumors
• Cowden syndrome, an inherited disorder that increases the risk of developing both benign (non-cancerous) and malignant (cancerous) tumors
• Peutz-Jeghers syndrome, a rare inherited condition that typically causes pigmented patches on the skin and polyps in the digestive tract

Possible Complications When Diagnosed with Colon Polyps

• Bleeding
• Diarrhea
• Bowel obstruction
• Cancer