It does this when I use it and I've had no ill effects. Although it should subside after a couple of hours.
Funny, I have probably used close to 50 litres of the stuff since it came out, and apart from a mild sulphur odour that emenates from the bottle, I have never had Prime smell anything like fæces, either in or out of the bottle.
does your prime smell like a wettish fart in an enclosed shower cubical with hot steam everywhere and water? If not then there may be a problem with it.....