Animals do not have a problem with it. Small children even play with it. So why are adult humans so disgusted by faeces? Ayesha Nunhuck investigates
Until my second year as a medical student, I was only familiar with aversion to faeces as some sort of humour. But the aversion is widespread: why are we so disgusted by our own excrement?
Valerie Curtis of the London School of Hygiene and Tropical Medicine believes rejection of bodily secretions, such as faeces, may be a biological mechanism for avoiding infectious disease (Anatomy of Disgust, Channel 4, 2000). More than 1011 bacteria are found in each gram of dry faeces; 40%-50% of the dry weight.1–3 Also, infected individuals excrete high numbers of viruses, such as cholera and typhoid.45 Generally, contamination by human excrement is regarded as the greatest risk to water supplies, with a huge resultant morbidity and mortality worldwide.56
When and how humans became averse to faeces is not known. One proposal is that our ancestors distancing themselves from faeces was to aid survival by concealing their scent