Appendicitis

Appendicitis is where the appendix becomes severely inflamed, forcing the appendix to be removed from the body before it ruptures which will cause sepsis and death.

In the Season 3 finale episode, Nemesis, Dr. Daniel Jackson was left bed-ridden after suffering from appendicitis. In real life, the actor who plays him, Michael Shanks came down with appendicitis, forcing the writers to reduce his scenes in "Nemesis" in order to give Shanks enough time to recover.