The phrase "rusty pipes" refers to pipes that have been damaged by rust, a reddish-brown substance that forms on metal. It can also be used figuratively to describe someone's singing voice if it sounds rough or out of practice. Full definition
Occasionally, blood from rusty pipe syndrome or cracked nipples can appear in your breast milk. (verywellfamily.com)
This is the part where you imagine the highly esteemed intellectual swinging from rusty pipes and punching bad guys all while keeping his tuxedo unwrinkled and fabulous. (relevantmagazine.com)
A small amount of blood in your breast milk is typically nothing to be worried about, and it's often the result of rusty pipe syndrome. (verywellfamily.com)