Cleanliness and an abundance of lubricant is very important!!
Like anything that gets inserted into our body, a butt plug needs to be clean. A good wash with soap will do. And you need to use plenty of lubricants, as well as go slow and start small. If you go to big it can cause “tears” that can become infected.
Though if you are prone to hemorrhoids, or have an onset of hemorrhoids, the proper use of a butt plug can reduce the pain and discomfort. Because a short butt plug will stimulate a kind of kegel exercise of the muscles around the butt hole. And those contractions will in turn help prevent a prolapse as well as improve the blood circulation.

At age 26 I had to have a hemorrhoids surgery, and got 3rd degree burns on my feet during recovery in the hospital. (Warm water bottles and anesthesia are a very nasty combination!) During the following 10 years I was constantly battling with minor hemorrhoids. And creams would only provide very temporary relief. Doing a finger massage of the sphincter gave somewhat better relief, but the mechanical angles were very awkward, to say the least. Then I got my first small butt plug. By using it in the shower for about 10 minutes three to five times a week I was able to reduce and eliminate the discomfort of hemorrhoids. Now at over 50 I do a weekly session with a short butt plug and and abundance of lubricant gel to remain free of hemorrhoids.

And I want to emphasize that cleanliness and an overabundance of lubricant are paramount. As well as keeping the diameter on the smaller side. Going slow is another very important factor. Do not overstretch!

As is the case for these types of discussions, the standard disclaimers apply: I am not a health care provider, nor do I play one on TV or YouTube. And when in doubt consult with your own personal health care provider.