Heard of someone with infection and rupture of his appendix , organ failure and on life support, how did he get it?

Rare: To have this occur, but any advanced or serious internal infection such as ruptured appendicitis, sometimes associated with other serious medical conditions of diabetes or heart or lung problems, could develop into a serious sepsis syndrome and multi organ failure. Not seen too often, but does occur rarely.

Sepsis: Sepsis is decreased oxygen perfusion to an organ causing failure due to an infection. Multiple organ failure doesnt happen often after or during appendicitis, but people who are elderly, or have multiple medical problems are more susceptible.