A colorectal exam, most commonly a colonoscopy, is a preventive procedure used to screen for colorectal cancer and to identify and remove precancerous growths called polyps. This examination involves inserting a flexible, lighted tube with a camera, known as a colonoscope, into the rectum and threading it through the large intestine. The primary objective is to visualize the colon lining to detect any abnormalities. Understanding the steps involved can help alleviate anxiety about the process, from preparation through follow-up.
Preparing for the Exam
The success of the colonoscopy depends on thorough bowel preparation, which aims to clear the colon of all solid stool so the physician can clearly see the intestinal wall. Preparation begins several days before the procedure with dietary and medication changes. You will be instructed to start a low-fiber diet, avoiding high-residue foods like nuts, seeds, whole grains, and raw fruits and vegetables with skins.
The day before the exam, you must switch to an exclusively clear liquid diet, consuming only liquids you can see through (water, broth, clear juices, and plain tea or coffee). Avoid red or purple liquids, which can mimic the appearance of blood. This fasting period is supplemented by a prescribed laxative solution, often split into two doses taken the evening before and the morning of the procedure.
Proper hydration is important during this time to replace the fluids lost from the laxative-induced diarrhea. You must discuss all medications with your doctor beforehand, especially blood thinners and certain diabetes medications, as these often need to be temporarily adjusted or stopped to prevent complications during the procedure. For example, blood thinners like warfarin may need to be paused for several days, while insulin and other diabetes drug dosages may need adjustment due to the restricted diet.
The Examination Process
On the day of your procedure, staff will confirm your medical history and review consent forms for the procedure and sedation. A nurse will place an intravenous (IV) line to administer fluids and the sedation medication. You will also speak with the gastroenterologist and often a member of the anesthesia team to finalize any questions about the process.
Most patients receive Monitored Anesthesia Care (MAC) or deep sedation, often involving Propofol, which allows you to sleep through the entire exam. Some facilities offer conscious sedation, where you are relaxed but not fully asleep, or no sedation at all. Once you are positioned on your side, the lubricated colonoscope is gently inserted through the rectum and advanced through the colon.
The physician carefully navigates the scope to the very beginning of the large intestine, a process called intubation, and then slowly withdraws it while examining the lining for polyps or other abnormalities. If the doctor finds a polyp, they will remove it immediately using specialized tools passed through the scope in a process called a polypectomy. Any tissue samples removed are sent to a lab for biopsy. The entire procedure is generally quite fast, typically lasting between 15 and 45 minutes.
Recovery and Follow-Up
Following the examination, you will be moved to a recovery area where nurses monitor your vital signs as the effects of the sedation begin to wear off. Because air is inflated into the colon during the procedure to help the physician see the lining clearly, a common and expected side effect is mild abdominal cramping, bloating, and the need to pass gas. Walking around slightly in the recovery room can help to expel this excess air and ease the discomfort.
Due to the lingering effects of the sedation, which can impair judgment and coordination for several hours, you are not permitted to drive yourself home and must have a responsible adult accompany you from the facility. Most people feel well enough to resume a normal diet and light activities the following day, though you should avoid making important decisions or engaging in strenuous exercise for at least 24 hours. If a polyp was removed, the doctor may advise avoiding heavy lifting for a few days to allow the site to heal.
The gastroenterologist will usually provide preliminary results immediately after you wake up, informing you if any polyps were found and removed. However, the definitive results from the tissue biopsies, which determine if the polyps were benign or precancerous, take longer, typically arriving from the pathology lab within one to two weeks. Your doctor will then communicate these final results and recommend the timeline for your next screening, which can vary depending on the findings.