The reason why the appendix becomes inflamed in the first place is not known in most cases. Some cases are thought to be due to a blockage that occurs somewhere along the short appendix. This may be due to some hard stools (faeces) that get stuck. It may also sometimes be due to bits of indigestible food being delivered from the small intestine to the large intestine. These should be forced out again by the muscles in the wall of appendix, but if they get stuck then blockage results. Either way, germs (bacteria) may then thrive and cause inflammation behind the blockage in the dead end of the appendix.