SDN Members don't see this ad. (About Ads) So I am on my surgery month and I am getting confused as to why they use certain tubes. For example, what does PEG stand for, and in what circumstances would a surgeon put one in? Why would a J tube be put in instead of a PEG? What is the difference between G tube and PEG? Similarly, why would someone put in a PICC line instead of a central line? I appreciate your answers! Thanks.