I have come across this online recently and decided to awnser it as truthfully and Honourestly as possible.
Here's my response to the question at hand
Yes is the awnser, in-fact as a incontinent person who has disabilities and has to wear diapers/nappies from time to time on a regular basis through-out the world,
This of cause being prior to this past year and a half and a half this is mainly due to covid-19 travel restrictions and the fact I can't just up and go anywhere as I have committments.
I've actually even done do in the past, when traveling through Hong Kong to the Philippines although I would recommend that you write this statement assuming your talking about adult sized disposable diapers.
The person who owns this suitcase has a genuine medical condition, and is incontinent please don't open the suitcase without the expressed permission of the owner.
Then write on that same note using a A4 peice of paper your flight details and your name and destination I've never had any problems as an adult although some other countries may be more stricter than others
However saying this you can take some in your hand luggage although that's more risky in terms of potential embarrassing situations, because everyone will know you have diapers in your bags.
However if you kindly send calmly inform them you have a medical condition or are disabled, and they are intended solely for your own use then in this case you shouldn't have a problem as most security airport staff are sympathetic because they get alot of
People who are in similar situations and therefore should be kind enough to let you go on your way without any issues.
Although I can't really say anything about the USA because the last time that happened was when I was a baby/toddler back in 1982 when mom had to open her suitcase because it was full of diapers/nappies for myself this happened at Miami.
Hopefully this will help awnser your questions.