Most of the basic skills are obtained during the 3 year-GI fellowships. Some People often pursue one more year of interventional GI for more sophiscated endoscopic surgeries. If your GI fellowship does not have any advanced fellowship, you can probably do a good number of interventional stuffs for practice. If the fellowship does have 4th year fellow(s), you will lose more interventional stuffs (i.e. ERCP, EUS, etc).
