A colonoscopy examines the interior lining of the large intestine (colon), typically to screen for cancer or investigate symptoms. For individuals with an ostomy, the procedure must be performed through the surgically-formed opening called a stoma instead of the rectum. Understanding this modified procedure can alleviate apprehension. The difference in the entry point changes the physical sensation and preparation for the patient.
Understanding the Sensation During the Procedure
The primary concern is whether a colonoscopy through a stoma will be painful. The stoma itself is a piece of bowel brought through the abdominal wall and does not contain nerve endings that register pain. Therefore, inserting the flexible camera tube (colonoscope) through the stoma opening should not cause sharp pain at the site.
Any discomfort experienced usually comes from the pressure within the bowel as the scope advances and the doctor introduces air or carbon dioxide. This inflation is necessary to gently open the colon wall for a clear view, but it can lead to feelings of bloating, cramping, or gas pain. This sensation is similar to the gas pains felt during a standard colonoscopy. The intensity of this pressure varies among individuals, often depending on the unique anatomy and the extent of the examination.
Conscious sedation is frequently administered to keep patients comfortable, making them feel relaxed and often resulting in no memory of the procedure. Propofol is a common sedative, though some patients may choose milder pain relief like Entonox (“gas and air”). If discomfort occurs, more sedation can be administered, or the procedure may be stopped. Sharp, localized pain is uncommon and should be reported immediately, as it may indicate an issue.
The cramping sensation, which is distinct from pain, is typically caused by the scope moving through the bowel’s bends and curves. Since the colonoscope enters through the stoma, it bypasses the sensitive rectum and anus associated with traditional colonoscopy discomfort. The overall experience is generally reported as being more about pressure and bloating than actual pain, especially with sedatives.
Why and How the Procedure Differs When Using a Stoma
A colonoscopy is performed through a stoma to examine the remaining large intestine after ostomy surgery. This is done for routine surveillance (screening for polyps or cancer recurrence) or to investigate symptoms like bleeding or changes in bowel habits.
The main procedural difference is the point of entry; the lubricated colonoscope is inserted directly into the stoma, which leads into the colon. This requires the endoscopist to exercise specialized care and precision to navigate the altered anatomy and protect the stoma site. The patient is typically positioned on their side, and the endoscopy team works carefully around the existing stoma appliance.
During the examination, air is insufflated into the bowel to stretch the walls for a better view, which is the same technique used in a traditional colonoscopy. The endoscopist may take small tissue samples (biopsies) or remove polyps using instruments passed through the scope. Neither taking a biopsy nor removing a polyp is typically felt by the patient, as the bowel lining does not have pain-sensing nerves.
The team protects the surrounding skin and stoma by removing the ostomy pouch just before the procedure. After the examination, which generally takes 30 to 45 minutes, a nurse specializing in stoma care or the endoscopy team applies a clean, fresh ostomy bag.
Specialized Preparation and Post-Procedure Recovery
Preparation for a stoma colonoscopy is often the most challenging aspect, requiring complete cleansing of the colon for clear visualization. Patients follow a clear liquid diet and consume a prescribed oral laxative solution the day before the procedure. The laxative causes profuse, watery output, necessitating specific stoma management.
Patients should switch to a large-capacity, drainable ostomy pouch during preparation to handle the high volume of liquid stool. This allows frequent emptying without changing the entire appliance, which helps protect the skin around the stoma. Staying well-hydrated with clear fluids is important to replace fluids lost from the laxative effects and prevent dehydration.
In the immediate post-procedure phase, the most common effects are bloating and the need to pass gas. The air introduced during the procedure needs to escape, and the stoma becomes the natural exit point. Patients are encouraged to move around or change position to help the gas pass, which can relieve the bloating and any residual cramping.
The stoma may appear slightly swollen or irritated following the colonoscope insertion, which is a temporary effect. This irritation should subside quickly, but the stoma and surrounding skin should be monitored for any unusual changes.
Recovery from sedation is usually straightforward, but patients must have an escort home and should avoid driving or making important decisions for 24 hours. Full recovery is typically quick, and patients can generally resume their normal diet soon after the procedure.