A sigmoidoscopy is a diagnostic procedure that allows the healthcare provider to examine the interior lining of the rectum and the sigmoid colon using a flexible or rigid lighted tube equipped with a camera. This procedure is commonly performed in Nigerian clinical settings for both screening and diagnostic evaluations. Unlike a full colonoscopy which inspects the entire large bowel, a sigmoidoscopy focuses strictly on the lower third of the colon.
Clinical indications for ordering a sigmoidoscopy include:
Understanding the anatomy of the lower gastrointestinal tract ensures safe passage of the sigmoidoscopy scope. The rectum is the final straight portion of the large intestine, measuring roughly twelve to fifteen centimeters, terminating at the anal canal. Directly above the rectum lies the sigmoid colon, an S-shaped loop of bowel that connects to the descending colon. Because the sigmoid colon has natural curves and mobility, navigating it requires gentle manipulation to prevent perforation.
The wall of the colon features distinct longitudinal muscle bands called taeniae coli and pouches known as haustra. During scope insertion, air is insufflated to distend the lumen for better visibility. This air stretching can trigger intense cramping if the patient's bowel is sensitive, requiring the nurse to monitor the patient's pain cues closely.
Thorough preparation before a sigmoidoscopy guarantees a clear field of vision and minimizes procedural risks. The nurse must verify that the patient has given informed consent, checking that the doctor has explained the procedure, risks, and benefits. Allergy history, bleeding disorders, and current medications—especially anticoagulants—must be documented.
Bowel cleansing protocols typically involve one or two enemas administered a few hours before the procedure, though some clinics use mild oral laxatives. Unlike a full colonoscopy, complete whole-gut lavage is rarely necessary for a flexible sigmoidoscopy. The nurse instructs the client to report any severe abdominal pain or dizziness during the prep phase.
During the sigmoidoscopy, the nurse plays a vital role in maintaining patient comfort, monitoring vital signs, and assisting the endoscopist. The patient is typically positioned in the left lateral Sims' position, with the knees flexed toward the chest. This position utilizes gravity to help the sigmoid colon fall forward, easing scope insertion and reducing patient discomfort.
The nurse continuously observes the patient's facial expressions, respiratory rate, and oxygen saturation. If sedation is used, pulse oximetry and blood pressure monitoring must follow strict institutional protocols. The nurse also manages light sources, suction equipment, and specimen containers if tissue biopsies are collected.
Once the scope is withdrawn, the immediate post-procedure phase begins. The nurse guides the patient to a resting area and instructs them to pass flatus to relieve trapped air, which significantly reduces abdominal distension and cramping. Vital signs are recorded at regular intervals until the patient is fully stable.
The nurse must remain vigilant for signs of complications, particularly bowel perforation or delayed hemorrhage. Red flag symptoms that require immediate medical notification include:
Before the patient leaves the health facility, clear discharge instructions must be provided verbally and in writing. The nurse explains that mild cramping and passing small amounts of gas or blood-tinged mucus are normal for the first twenty-four hours, especially if a biopsy was taken.
Dietary restrictions are usually minimal unless specialized interventions were performed; most patients can resume their normal diet immediately. The nurse stresses the importance of contacting the clinic or returning to the emergency unit if warning signs such as heavy bleeding, severe pain, or fever develop. Finally, the nurse confirms that the patient has a designated person to accompany them home if sedation was administered.