In general, a flexible sigmoidoscopy is a very safe procedure. Complications are rare, occurring in less than 1% of patients. Most complications are not life-threatening, but if a complication does occur, it may require hospitalisation and surgery. Before the exam, the nursing staff will go over a consent form with you, and you can discuss any questions or concerns with your physician before the procedure begins. Bleeding can happen if biopsies are taken or polyps are removed during the sigmoidoscopy. However, significant bleeding that requires a blood transfusion or hospitalization is very uncommon. If bleeding does occur, it can happen at the time of the exam or up to 2 weeks after if a polyp was removed. There is a small risk of the colon being perforated or punctured during the procedure. This may be noticed right away or it may become apparent later in the day. If a perforation occurs, it will usually require surgery and hospitalization. However, this is a rare complication, even when polyps are removed. It's important to contact your doctor's office immediately if you experience worsening abdominal pain, bleeding, or fever after the procedure. Like any test, a sigmoidoscopy is not perfect and there is a small chance that abnormalities, including polyps and cancers, may be missed during the exam. It's important to continue following up with your doctors as instructed and inform them of any new or persistent symptoms. If you have any questions or concerns, please speak with your specialist.