Whilst reading Purity and Danger by Mary Douglas, I come across an interesting paragraph, one that I had also seen quoted within Julia Kristeva's Powers of Horror.
Matter issuing from them [the orifices of the body] is marginal stuff of the most obvious kind. Spittle, blood, milk, urine, faeces or tears by simply issuing forth have transversed the boundary of the body. [...] The mistake is ti treat bodily margins in isolation from all other margins.
-Mary Douglas, Purity and Danger, P.122