Questions I have about a Flexible sigmoidoscopy

Has anyone ever had a Flexible sigmoidoscopy?? Did your doctor take you off of the meds you are on before having to do the Flexible sigmoidoscopy?? If so, did they have you continue them after the Flexible sigmoidoscopy?? Also, does the Flexible sigmoidoscopy see up to the lower left of the colon that is at least 20" from the rectom?? Because that is where the constant dull ache is for me even on the meds I have been on for almost a year. Do they put you to sleep for the Flexible sigmoidoscopy??