A colonoscopy is a common medical procedure used to examine the large intestine, also known as the colon. It assesses the inner lining of the bowel and is a well-established method for investigating various digestive conditions.
Why a Colonoscopy Is Performed
A colonoscopy is primarily for detecting and preventing colorectal cancer. It identifies and removes precancerous growths called polyps, which can develop into cancer over time. This dual capability makes it both a diagnostic and a preventative tool, distinguishing it from other screening methods. It combines the ability to detect abnormalities with the immediate capacity to treat them.
Beyond cancer screening, a colonoscopy diagnoses other gastrointestinal conditions. These include inflammatory bowel disease (IBD), such as Crohn’s disease or ulcerative colitis, and diverticulosis, a condition where small pouches form in the colon wall. It also investigates unexplained symptoms like chronic abdominal pain or bleeding from the lower digestive tract.
When to Consider a Colonoscopy
The decision to undergo a colonoscopy depends on individual risk factors and symptoms. For average-risk individuals, routine screening begins at age 45. If the initial colonoscopy reveals no polyps or other concerns, the next screening is recommended after 10 years. Screening for average-risk individuals continues through age 75.
Certain factors necessitate earlier or more frequent colonoscopies. A family history of colorectal cancer, particularly in a first-degree relative, or a personal history of certain polyps, increases this risk. Screening might begin at age 40, or 10 years earlier than the youngest family member’s diagnosis. Individuals with inflammatory bowel disease (ulcerative colitis or Crohn’s disease) also face an elevated risk, requiring screening 8 to 10 years after symptom onset, with subsequent tests every one to three years. Inherited genetic syndromes, like Lynch syndrome or familial adenomatous polyposis (FAP), also warrant earlier and more frequent screening, sometimes as early as age 10 for FAP.
A diagnostic colonoscopy may be recommended at any age if certain symptoms are present. These include persistent changes in bowel habits, such as unexplained diarrhea, constipation, or alterations in stool frequency or shape. Rectal bleeding or blood in the stool also warrants investigation. Other concerning symptoms are unexplained abdominal pain or cramping, unintended weight loss, or persistent fatigue due to unexplained anemia. While not always serious, these symptoms warrant medical evaluation to determine the underlying cause.
What to Expect During a Colonoscopy
Preparing for a colonoscopy involves dietary adjustments and bowel cleansing. Patients follow a low-fiber diet for a few days, transitioning to a clear liquid diet the day before. This preparation includes consuming prescribed laxative solutions, often in divided doses the evening before and morning of the procedure, to ensure the colon is clear. Fasting from solid foods for at least eight hours and clear liquids for two hours before the appointment is required.
During the colonoscopy, a flexible tube with a camera, called a colonoscope, is inserted through the anus and advanced into the colon. Air or carbon dioxide is introduced to expand the colon, providing a clearer view of the lining. For comfort, patients receive sedation, ranging from conscious sedation to deep sedation or general anesthesia. Propofol is a commonly used medication for deep sedation due to its rapid action and quick dissipation. The procedure takes between 15 and 60 minutes, during which polyps can be removed and tissue samples taken for examination.
After the procedure, patients are monitored in a recovery area while sedation effects wear off. Drowsiness, grogginess, or light-headedness are common for several hours. Due to sedation, arrange for someone to drive you home. Mild abdominal discomfort, cramping, and bloating are also common due to air introduced during the procedure.
After Your Colonoscopy
Following a colonoscopy, rest for the remainder of the day and avoid strenuous activities for at least 24 hours. Staying hydrated by drinking plenty of fluids is recommended. Mild gas and bloating are common as the body expels air introduced during the procedure; light walking can help alleviate this discomfort. Temporary changes in bowel movements, such as mild diarrhea or constipation, may occur but normalize within a few days. If polyps were removed or biopsies taken, a small amount of light rectal bleeding with the first bowel movements is common.
Your doctor will discuss the colonoscopy findings with you. If no polyps were found and the colon was healthy, the next routine screening is recommended in 10 years. If polyps were discovered and removed, surveillance colonoscopies will be recommended at specific intervals, such as every three or five years, depending on the number, size, and type of polyps found. This ongoing surveillance aims to detect any new or recurrent polyps and reduce the risk of colorectal cancer. While complications are rare, contact your doctor immediately if you experience severe abdominal pain, heavy rectal bleeding, fever, chills, or persistent nausea and vomiting.