Urine

I have recently noticed a pinkish residue in the toilet bowl after urinating. Even after a flush the very light pink color is distributated evenly in the area of the standing water. I have just recently been to my urologist for a very complete check-up and forgot to mention this to him as it has occured some months ago for a short time.
I have eaten a lot of watermellon the day before and drink Merlot. What do you think?

There is a type of fungal growth that occurs in toilet bowls and bathtubs etc, which is also light pink, have you thought of that?

Thanks for your reply. I clean the toilet bowl with a Lysol bowl cleaner after seeing the pink residue. It does not occur everytime I urinate. So far it looks like watermellon even after two days.