As Harper watched on, Drew waded into the water. Dressed in only his undies, he ventured down the hallway to see where the water was coming from.
As a look of horror spread across his face, he yelled back to Harper: "It's a poo-nami!"
For several grim, agonising moments, Drew slipped then floundered around in a sea of raw sewage - complete with faecal matter floating by.
The scene ended with Drew meekly saying: "Help me."
"I'm pregnant with bad morning sickness and I started gagging real bad at this scene," wrote one distraught viewer on Facebook.
But Barrington, who filmed the scene weeks ago, says no real faecal matter was used during the scene.
In fact, he had "lots of fun" making the poo-nami happen.
"The water was nice and warm ... It was like being back on the hydro-slide when I was a kid, before they cleaned the place up."
Also, the Herald can exclusively reveal exactly how the poo-nami poos were made.
"The poos were made from a high energy mixture of gingernuts, coffee and raisins," says Barrington.
"So once we had finished filming – everyone on the crew enjoyed a nutritious snack!"
Still, the scene has left viewers wondering what they had witnessed, with one asking: "What even is Shortland Street now?"
Others expressed disgust at the show airing a scene involving raw sewage at a time when they were eating dinner.
The "poo-nami" scene comes just over a year after Shortland Street sparked international headlines with a scene involving Chris Warner declaring, "Please tell me that is not your penis!" after finding a nude photo of his son on an iPad.
The line was named the Quote of the Year for 2017.
