A doll that goes number-two is said to be the number-one best seller with little girls ... but are uber-realistic playthings good for our kids?

"Sniff sniff," "I made a stinky!" No that's not your toddler alerting you to a potty training accident. It's her doll. Hasbro's new Baby Alive doll lets you know when she's made "poo" in her doll potty.

Dolls have been "wetting" themselves for years, but now toy makers are upping the bodily-function ante -- and dolls are now capable of going number two. Ew!

The instructions for this year's model of Baby Alive (retailing for $59.99) say "just like real life, sometimes she can hold it until she gets to the 'potty' and sometimes she can't!". A warning on the back of the box reads: "May stain some surfaces."

Yick. What happened to good old-fashioned make-believe?

Susan Linn, professor of child psychology at Harvard and director of the Campaign for a Commercial-Free Childhood, says, "This toy is shocking enough that it's going to be noticed. But at best, this toy is unnecessary. At worst, it's really gross."

She says this doll is part of a greater trend to create toys that do everything. "And in the process of marketing those toys to children and flooding the market with those toys, what we're doing is depriving children of opportunities for creative play," says Linn.

What do you think? Are dolls that go "poo" taking realism a bit too far? Comment in the momlogic community.