Butt garments
Butt garments is a CWC-ism for diapers, which are used to prevent DIRTY, CRAPPED BRIEFS (or fecal incontinence, where one unintentionally shits themselves). He most likely called them "butt garments" to avoid the embarrassment of wearing diapers, despite the fact that he desperately needs them, after refusing to do a diet or exercises that the doctor recommended him. Chris hated the idea of wearing diapers, and made multiple attempts to throw out the diapers before Barb caught on and hid them away in her hoard room.[1]
Since coming out as a trans woman, Chris has chosen to wear maxi pads. Although he is unable to menstruate, these pads have similar moisture-absorbing properties and are large enough to function as adult diapers. It is very probable that these maxi pads now serve as his new butt garments.
Discovery
On 16 April 2009, images of Chris in diapers leaked, with a special shout-out to spas from #sonichu. Chris later stated in ECV 00095 that the butt garments were sent to him by a troll. According to Ivy's ghost, Barbara mistook them for samples of adult diapers sent by Chris's doctor, who had been trying to convince Chris to start wearing them.
After Ivy found out that Chris was cheating on him with Vanessa Hudgens, one of her friends suggested that he take the photos below to apologize to Ivy. The front reads "TOO HOT FOR COLLECTION," in case you don't want to stare at it for too long. This appears to have been the last time they were ever mentioned. Presumably, they are (or, possibly, were) still sitting around Barbara's bedroom.