Colonoscopy

A colonoscopy is the most accurate method for detecting colon cancer at an early stage when treatment is most effective. It also allows for detecting inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis, which cause chronic inflammation of the intestines.

A colonoscopy is recommended if you have symptoms that may indicate a problem with the large intestine, such as blood in the stool (either bright red or dark), changes in bowel habits like persistent diarrhea or constipation, narrowing of the stool, a feeling of incomplete evacuation, ongoing abdominal pain, bloating, or cramping, as well as sudden weight loss or unexplained fatigue. It is also used to monitor patients with previously detected rectal abnormalities and those with positive fecal occult blood test results.

Colonoscopy is an essential preventive, diagnostic method that can help detect severe conditions such as colorectal cancer at an early stage. For most individuals without symptoms and a family history of colorectal cancer, routine screening is recommended starting at age 50. For individuals with a family history of colorectal cancer, preventive screenings should begin earlier, typically at age 40.

Without proper preparation, a high-quality colonoscopy is not possible. Your doctor will advise you to follow a specific diet for a few days before the exam. This diet usually includes easily digestible foods such as egg whites, boiled chicken or fish, white bread, cooked potatoes, rice, peeled vegetables, and liquids like broth, tea, or coffee (without milk). You should switch to a completely liquid diet the day before the procedure. Recommended fluids include clear broths, water, pulp-free fruit juices, tea, and coffee—solid food should be avoided entirely.
One of the most critical steps in preparation is thorough bowel cleansing using laxatives or special solutions prescribed by your doctor. It’s also crucial to stay well-hydrated (avoiding milk and alcohol) to prevent dehydration. On the day of the procedure, do not eat or drink anything unless instructed otherwise by your physician.

A colonoscopy is performed using a long, flexible instrument called a colonoscope, which is inserted through the anus to examine the lining of the entire large intestine. During the procedure, the patient lies on their side, and the body position may be adjusted as needed to improve the visibility of some regions of the colon.

After colonoscopy, rest is recommended for the remainder of the day when performed under general anesthesia. Patients should avoid driving and making essential decisions until fully alert. Common side effects include mild bloating, gas, or cramping due to the air introduced during the exam—these typically resolve within a few hours. Light bleeding may occur if polyps are removed or tissue samples are taken. In case of heavy bleeding, severe abdominal pain, fever, or any unusual symptoms, contact your doctor immediately.