Symptoms of Bacterial Infection After Colonoscopy
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Medically reviewed by Jay N. Yepuri, MD, MS
A colonoscopy is a procedure that’s used to look inside the colon (large intestine). A flexible tube with a light and a camera on the end is inserted into the anus and up through the rectum and the large intestine.
This test is done to screen for colon and rectal cancers, and as a way to make a diagnosis of various other digestive conditions. It is a necessary and safe procedure. In rare cases, a bacterial infection is possible after having a colonoscopy.
This article will discuss the symptoms of bacterial infection after a colonoscopy. While it’s not likely to happen, it’s good to know what the signs and symptoms are.
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Infection Rates After Colonoscopy
The rate of infection in the digestive system after having a colonoscopy is low. One study included 112,543 people who had either colonoscopy or sigmoidoscopy (which looks at the lower part of the colon with a flexible viewing tube).
The number of people who had an infection within 30 days after the procedure was noted. The overall rate was found to be 0.37%.
The infection rates broken out by procedure were:
Colonoscopy without invasive intervention (such as polyp removal): 0.41%
Sigmoidoscopy without invasive intervention: 0.25%
Endoscopic biopsy (a sample of tissue is removed during the test for testing): 0.28%
Endoscopic polypectomy (removal of a polyp during the test): 0.26%
Treatments During Colonoscopy
Treatments can be done during a colonoscopy. The most common of these is the removal of a polyp, which is a growth on the inside of the colon. Removing a polyp is important to prevent colon cancer, but may cause some minor bleeding.
Related: What Are the Types of Colon Polyps?
The types of infection that occurred were also varied. The most common infections were:
Diverticulitis (an infection involving the colon): 38%
Peritonitis (an infection of the inner wall of the abdomen): 26%
Appendicitis (an infection of the appendix): 13%
Osteomyelitis (an infection of the bones): 8%
Pyogenic liver abscess (a pocket of fluid in the liver): 6%
Septic pulmonary embolism (an infection in the lungs): 2%
Symptoms of Infection After Colonoscopy
An infection that happens after a colonoscopy may cause signs and symptoms. When leaving after a colonoscopy, people will be given some guidance on what to look for and which symptoms are a reason to call a healthcare provider.
Symptoms of an infection after a colonoscopy could include one or more of the following:
Abdominal tenderness
Chills
Nausea
Vomiting
Sepsis is a life-threatening infection. It occurs when an infection in the body gets into the bloodstream. It’s important to know the symptoms of sepsis because it needs to get treatment right away.
The symptoms of sepsis can include:
Fever, followed by hypothermia (low body temperature)
Sweating
Tachycardia (rapid heart rate)
Tachypnea (rapid breathing)
When to See a Healthcare Provider
You will be given instructions on when to contact your healthcare provider after a colonoscopy. A certain amount of abdominal discomfort may be part of the recovery process. Some people will have intestinal gas and this may be uncomfortable until it can be passed.
When a polyp has been removed, there could be bleeding from the rectum. Polyps are the precursor to colon and rectal cancer. If one is found during a colonoscopy, it is usually removed, and a small amount of blood may pass out of the rectum afterward.
However, these symptoms shouldn’t be severe, and they should go away within a day or so. If symptoms go on for too long or are really troublesome, it’s time to contact a healthcare provider.
Symptoms to watch for after a colonoscopy include:
Abdominal pain or cramps, especially if it is worsening
Bleeding from the rectum that’s severe or that goes on for too long
Chills
Fever
Related: Recovering From a Colonoscopy: What to Expect
Other Colonoscopy Risks and Complications
While a colonoscopy is effective in screening for colon and rectal cancer, there are some risks. These risks include:
Sedation: A reaction to the anesthetic, such as an allergic reaction, can happen any time anesthetic is used.
Aspiration pneumonia: This lung infection, caused by inhaling secretions into the lungs, is rare but it is another potential risk with anesthesia.
Perforation: Colonoscopy tools used during the procedure can puncture the intestine. It is a rare occurrence that may cause abdominal pain and rectal bleeding. Treatment varies based on the severity of the perforation.
Post-polypectomy electrocoagulation syndrome may cause pain after a polyp is removed during a colonoscopy. It’s caused by damage to the inner layers of the colon and leads to inflammation. It's rare and may happen more frequently with the removal of larger polyps.
Are Colonoscopies Safe?
Complications are uncommon to rare with colonoscopy. The usefulness of the test in preventing and screening for colon and rectal cancer outweighs the risks.
There are some people for whom the benefits may not outweigh the risks. This might be true for people who are older, who have digestive conditions, or who have other conditions that may make the procedure carry more risk.
Reducing Risk
There are some risk factors for having an infection after a colonoscopy that are fixed. However, it’s good to know if your risk might be higher because of these things.
Some of the risk factors include:
Being older than 70 years old or younger than 19 years old
Being male, as males had a higher rate of infection than females
Being hospitalized or having another gastrointestinal endoscopic procedure in the 30 days before the colonoscopy
Having inflammatory bowel disease (IBD, which includes Crohn’s disease or ulcerative colitis)
Data are lacking, but it appears that Black Americans and Native Americans may have higher rates of infection than White Americans after colonoscopy.
If you have concerns, ask questions. It’s worth first asking if the procedure is necessary, especially when there is a risk factor that can’t be changed (such as age), or if there is an alternative. You can ask about safety precautions, and tell your gastroenterologist or other healthcare provider your concerns about avoiding infection.
Questions to Ask
Endoscopy centers will have a staff member who cleans scopes. Scopes are usually tagged in some way as being clean after they've been processed. Peter Higgins, M.D., Ph.D., director of the IBD program at the University of Michigan, recommends asking these questions:
How are clean scopes identified?
How are the scopes monitored for bacteria after being cleaned?
How often are the scopes cleaned?
Summary
A colonoscopy can help detect colon and rectal cancer or help in diagnosing other diseases and conditions. It’s recommended that even people of average risk of colon and rectal cancer get a screening scope.
The risks of any complications are low. While infections and other complications of a colonoscopy are not common, they occur. Talk to your gastroenterologist about the procedure and any potential risk factors.
Frequently Asked Questions
How long after a colonoscopy can complications arise?
Many of the studies on complications after colonoscopy track patients for 30 days. If there’s a complication, it might be known soon after the colonoscopy because symptoms might begin in the days following the procedure. Some potential complications may start soon after the procedure but be longer-lasting, such as aspiration pneumonia.
Is it normal to have abdominal pain two weeks after a colonoscopy?
Abdominal pain that continues for two weeks after a colonoscopy is a reason to talk to a healthcare provider. Some people may have gas, bloating, or discomfort in the first few days after a colonoscopy. Having abdominal pain that goes on for longer than that could mean there is a problem that needs to be treated.
Can you get sepsis from having a colonoscopy?
Sepsis is an infection in the blood. If a person develops an infection after having a colonoscopy, sepsis could result. However, this is a rare occurrence. One study showed that the number of people who had bacteria in their blood after a colonoscopy was two or three per 100,000.
Bacteria in the blood could lead to sepsis, but this doesn’t always happen. Therefore, the rate of sepsis would be even lower than that of people with bacteria in their blood.
