Lesnar – a six time WWE champion – revealed the gross out story during a rare interview at an event in Canada.
The 41-year-old normally keeps himself to himself, letting his advocate Paul Heyman do the talking for him.
He dropped a bombshell however when he revealed what happened when he wrestled The Big Show when the 7ft 2in, 500lb, star hard a funny tummy.
Speaking at a live event to sports broadcaster Rod Pedersen he revealed the tale to those in attendance.
Lesnar’s disgusting yarn however has since been revealed online so all WWE fans can revel in the image of Brock smeared with poo.
“Lesnar slammed him to the canvas and his opponent exploded with diarrhoea all over him”
Lesnar’s interview with Rod Pedersen
Lesnar recalled a fight with the giant in the early 2000s – who he feuded with over the WWE title back in 2002.
He revealed that the giant athlete had been suffered from a bad bout of food poisoning but decided to compete.
The Beast in his usual monstrous fashion, went to slam his rival onto the mat at the show in South Africa.
And as he did, Big Show’s funny tummy gave when and suddenly the poo “exploded”.
In notes on the event released via Fightful, it said: “Before long he was doing 300 shows per year around the globe and while he was making millions, it became a real grind.
“However, he was never afraid of hard work.
“Lesnar told the amusing/disgusting story of how, one night during a show in South Africa, The Big Show had food poisoning.
“Lesnar slammed him to the canvas and his opponent exploded with diarrhoea all over him.”
It wouldn’t be the first time that a WWE wrestler has gone public about pooing themselves during a match.
CM Punk – who famously quit the company – claimed he pooed himself during a match with Dean Ambrose
John Cena also revealed he once puked under the ring due to food poisoning, only to then also crap his pants.
And even Stone Cold Steve Austin claims he once took a slam from Yokozuna, with the impact leaving him with poo in his trunks.
Lesnar hasn’t been seen in WWE since he was dethroned by Seth Rollins as WWE Universal Champion at WrestleMania.
The Beast has been a dominant force with the company since returning to pro-wrestling after a string in UFC back in 2012.
He is one of the most decorated pro-wrestlings ever, winning the WWE Championship four times and the WWE Universal Championship twice, holding the latter a total of 659 days.
Rumours are now running wild Lesnar could be in with a return to MMA as he steps back from WWE.