If you're thinking of the same thing I am, then it's different. In some places, the only option may be to defecate on the side of the street by the curb, but that area gets swept frequently. I have never been able to play a dog vs human sidewalk poo guessing game as suggested above, including in the African, Asian and LatAm slums.

Perhaps it's because those people are not a transient homeless population that (presumably) gets cleaned up after, but they actually live there.