4. Human Centipede 2: Full Sequence (2011) - Diarrhoea! Cha cha cha! Diarrhoea!
A revolting film with a revolting concept - stapling people ass to mouth to become a 'human centipede', Human Centipede 2: Full sequence elaborates upon the first movie and creates a longer centipede which features ten poor unfortunates stapled together. Another film with plenty of egregious material, for me, the absolute pinnacle of disgusting scenes in the movie was when centipede creator, Martin Lomax injects each of the 'components' of the centipede with laxatives and they all explosively defecate into each other's mouths. This is needlessly provocative and is only in the film to disgust. The whole film is just made to disgust, but the glee in Martin Lomax's face as he injects his 'pet' full of laxatives is just sheer overkill in the vile stakes and will surely ensure that Human Centipede 2 will be canonised in the Gross Out Film genre for all eternity.