You will see this color when you get scale and that is from not being scrubbed. Iron in hard water can also color if not scrubbed.
I live with the hardest water on the planet i think and if i don't use a pumice stone 2x monthly I get an orange ring.
Ask him to not flush after urinating if you are worried that he is peeing blood. If he won't comply go in right after him, you may be able to smell the blood.
Are water supply pipes something other than copper? Are they galvanised pipe? Those will disintegrate over many years of use and cause a red color. Or could be the water supply you are on. A well? Minerals in the water. Public Water Department? The Health Department may be setup to perform water tests.
You will see this color when you get scale and that is from not being scrubbed. Iron in hard water can also color if not scrubbed.
I live with the hardest water on the planet i think and if i don't use a pumice stone 2x monthly I get an orange ring.
Ask him to not flush after urinating if you are worried that he is peeing blood. If he won't comply go in right after him, you may be able to smell the blood.