president will transfer temporarily power to vice president kamala harris today as he undergoes a colonoscopy where he ll be under anesthesia. the president is at walter reed medical center right now for his annual physical, his first since taking office. joining me is cnn s chief medical correspondent dr. sanjay gupta for more. talk me through what it means that the president is getting a colonoscopy. so, this is a procedure, a screening procedure to try and determine if someone is developing any kind of polyps or anything worrisome for colon cancer. it s recommended for really anyone over the age of 45 at periodic intervals. so when you had this procedure, most typically, you re sedated with a medication like propofol or something. that doesn t mean your breathing is taken over or a breathing tube is placed into your trachea. it s a sedation to make the procedure more comfortable. typically takes less than about