The 53-year-old TV and radio presenter was asked by Phillip Schofield and Holly Willoughby how he was feeling after having a phlebectomy last week, to remove varicose veins in his legs.
Evans asked them “Do you wanna see? Do you wanna look?” as he began to unbuckle his belt live on the ITV show.
Schofield asked him: “Are you about to take your trousers down? What sort of pants have you got on? They’re not teeny pants?”
Evans replied: “No, I don’t have any teeny pants! Do you have teeny pants?”
The Virgin Radio DJ then pulled down his trousers and explained: “I had my varicose veins microwaved last week. And you have them taken out and the aftermath is ongoing. See all this?
“They used to laser, they now microwave and they used to strip. So you get them stripped out. Emma Thompson said, and she’s had children, she said: ‘Up there with childbirth having your veins stripped out.’
“But the thing is that what they’ve found out is that if you prune a bush, it comes back, doesn’t it. So if you prune your veins they come back… I don’t know how to get my trousers back on now… I need a copy of the paper!”
Read more: BBC top 10 highest-paid stars revealed
Varicose veins are swollen and lumpy veins that can become painful and appear blue or purple on the surface of the skin. The former Top Gear presenter’s varicose veins were caused by running.
Last week he shared a video of his surgery on the Virgin Radio UK Instagram account, followed by a clip of him jogging to the pub afterwards.
Prof Mark Whiteley carried out the operation, along with his wife and assistant Michelle, who told the camera: “We don't usually do these anymore unless they are very big but Chris has some whopping veins."
Evans was a guest on This Morning to discuss his annual Carfest weekend, which raises money for UK children’s charities.
He surprised the hosts by donating £40,000 from his CarFest fund to Together For Short Lives, the charity for which Willoughby is a patron, and a children’s hospice in Henley that Schofield supports.