blood

[gerkin]

what makes red blood cells red.

[auntie sar]

A pigment in your haemaglobin called bilirubin. When the red blood cells die it is mixed with a chemical from your spleen which makes it water soluble.

It is then passed as a waste product and is what makes your poo brown.

[gerkin]

thanks,

I thought bile made your poo brown ?

[morg_monster]

From wikipedia: "bile serves as the route of excretion for the hemoglobin breakdown product (bilirubin) which gives bile its colour"

so you are right too gerkin.

[Jennykins]

Oxygen..