If Bowling for Columbine was a combat sport, it would be unlicensed boxing. Brutal as hell, and no-holds barred. Moore certainly takes the gloves off towards the end.
Essentially, a documentary is an expression of opinion from whoever is behind it, and it is important to keep this in mind when approaching any film of this genre. In this case, the documentary in question is the brainchild of Michael Moore, the notorious left-wing American film-maker. In response to the massacre of thirteen students at Columbine High School in 1999, Moore sets out to question the gun laws in certain states of America; namely Michigan (Moore’s birthplace), and Denver (the state in which the massacre took place).