Diverticulitis and colon cancer share some similar symptoms, risk factors, and diagnostic tests. Research suggests there may be a link between the two conditions, and having diverticulitis may increase the risk of colon cancer.
Diverticulitis and colon cancer both involve the colon, which forms part of the large intestine. Colon cancer is cancer that starts here.
Diverticulosis occurs when a small pouch, called a diverticulum, forms on the colon. Doctors refer to multiple pouches as diverticula. Diverticulitis occurs if the pouches become inflamed.
This article explains the link between diverticulitis and colon cancer and whether having one of these conditions increases the risk of developing the other. It also explores the symptoms, diagnosis, and treatment of both conditions.
A 2024 cohort study examined whether diverticulitis increases the risk of colon cancer. The study looked at data from between 1997 and 2009 from a group of the Danish population.
The group included 29,173 adults with diverticulitis and a control group of 145,865 adults without diverticulitis. The groups matched for sex and age.
The diverticulitis group had a 2.1% risk of colon cancer compared with a 1.9% risk in the control group. People with complicated diverticulitis had an increased risk of colon cancer compared with those with uncomplicated diverticulitis.
The study found an increased risk of a colon cancer diagnosis in the first 6 months after a diverticulitis diagnosis.
After this time frame, the study found a reduced risk of colon cancer in people with diverticulitis for the 8 years following diverticulitis diagnosis compared with people in the control group. This may be due to increased screening.
Researchers recommend a follow-up colonoscopy after an initial diverticulitis diagnosis.
Additional research
Other studies on this relationship include a 2018 review of 31 studies, involving 50,445 people, which looked at the prevalence of colorectal cancer in people with acute diverticulitis.
Across the studies, the prevalence of colorectal cancer was 1.9%. The research also found that people with complicated diverticulitis were more than 6 times as likely to have colorectal cancer compared with people with uncomplicated diverticulitis.
Additionally, a
Symptoms of diverticulitis
- abdominal pain, usually in the lower left side of the abdomen
- constipation or diarrhea
- nausea or vomiting
- fever and chills
Diverticulitis pain can be severe. In other cases, it may be mild and worsen or change over time.
Symptoms of colon cancer may not appear until cancer progresses but can include:
- changes in bowel movements, such as:
- constipation
- diarrhea
- narrow stools lasting for
more than a few days
- bright red bleeding from the rectum
- blood in stool or dark brown or black stools
- still feeling the need for a bowel movement after having one
- abdominal pain or cramping
- weakness and fatigue
- unexplained weight loss
- anemia
According to a
In particular, a low fiber diet may play a role in both conditions. A low fiber diet may increase contractions and pressure in the colon, which can contribute to a diverticulum forming.
A lack of fiber can also affect movement through the colon, which may increase the risk of colon cancer.
Changes to how cells grow and divide may also link diverticular disease and colorectal cancer. By-products of bacteria may build-up in diverticulum, potentially contributing to cancer formation.
The
Other risk factors
Other causes and risk factors of diverticular disease
- lack of exercise
- certain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids
Other risk factors for colon cancer
- type 2 diabetes
- low vitamin D levels
- cooking meat at very high temperatures
- drinking alcohol
Age, race, and other health conditions, such as inflammatory bowel disease (IBD), can also affect the risk of colon cancer.
Diagnostic tests for diverticulitis and colon cancer may be similar.
According to the
- a physical exam, which may include feeling the abdomen and inside the rectum
- blood tests
- a stool test
- imaging tests, such as:
- a CT scan
- an MRI scan
- an ultrasound
- colonoscopy
According to a 2018 review, doctors usually use CT scans to diagnose diverticulitis, but the findings can result in misdiagnosis between diverticulitis and colon cancer.
For this reason, experts recommend a colonoscopy for people with diverticulitis, although this is controversial due to the potential risks of colonoscopy. The researchers suggest people with a high risk of colorectal cancer may benefit from colonoscopy.
Doctors may recommend a colonoscopy after a first-time diagnosis of diverticulitis. They will typically perform a colonoscopy after treating diverticulitis with antibiotics.
People may need medical treatment for diverticulitis if they also have complications. Treatment
- antibiotics
- a temporary clear liquid diet
- pain medications
- for severe complications, people may need surgery to remove part of the colon
Treatment for colon cancer can depend on the stage of cancer but
- surgery to remove the cancer
- immunotherapy
- chemotherapy
- radiation therapy
- targeted therapy
People who have any symptoms of diverticulitis or colon cancer need to contact a doctor. Symptoms may be due to another condition, but it is important to find the underlying cause.
If people have diverticulitis, it is also important to monitor for signs of complications or colon cancer, as people with diverticulitis may have an increased risk of colon cancer, particularly with complicated diverticulitis.
There is conflicting research on the link between diverticulitis and colon cancer, but recent studies suggest there may be an association between the two conditions.
Diverticulitis may increase the risk of colon cancer. However, it may also lead to increased screening, which can help protect against colon cancer. Complicated diverticulitis may increase colon cancer risk more than uncomplicated diverticulitis.
It is unclear whether having colon cancer increases the risk of diverticulitis.