Slit pants are pants or shorts with a vertical slit at the rear that runs along the crack all the way down to the crotch. Such pants are mainly worn by babies and toddlers in the streets of China. Chinese parents find them convenient as they allow their child to urinate or defecate quickly when needed. In such pants, the kids wear no underwear, so all they need to do in an emergency is to squat.
Slit pants for small children can be bought in normal shops in China. The kid's bare bottom is partly visible through the slit when walking, which is why some people find such garments embarrassing, while others find the sight cute. People are nowadays arguing in favor or against such slit pants: some find them practical and preferrable to diapers, others feel that the practice of letting one's child "go" in the streets is no longer acceptable in modern, especially urban, society.