I have a question. I know that one is allowed to throw out a diaper on Shabbos. Is it permitted to move a diaper on the changing table, while changing the baby, to make room to put on a new diaper?
Thank you for your question.
Dirty diapers are muktza on Shabbos, and essentially may not be moved. However since they are disgusting, there is a special heter called “graf shel rei”, (lit. a bedpan), which is that a disgusting or aesthetically disturbing item may be removed, and taken away from where you go on Shabbos, because it is not kavod habrios. This is why we are allowed to throw the diaper out on Shabbos, and by the same means since you need the place of the diaper while you are changing the baby, you can remove it. The best thing though, is to put the diaper into the pail straight away while you are still holding from taking it off the baby, because then you are only moving it once. If that is hard on you you can remove it afterwards.
Beitza 36b, O:CH 308-34 M:B 308-136, Aruch Hashulchan 308-60. Although it is permitted to move a graf shel rei, if it is possible to avoid it easily, this is preferred. For example according to some poskim if there is a gentile that can remove it, that it preferred. We also see that there are poskim that say that if possible the graf should be moved with a shinui, and from the halacha that we try not to create a graf shel rei, we do see that when it is possible to avoid coming on to this heter, that is preferred. Poskim