If you are in the USA, on a 6 month holiday visa, are you allowed to travel to other countries at that time?

He currently lives in England, but his home country is Italy. If he is coming to USA on 6 month visa, can he travel back to England or Italy during that time?

NO your visa is only valid (recognized )by US only you would ahve to apply based on your country citizenship to other countries consulates or embassy and meet the criteria of the host country you plan on visiting

no, you need to get a visa from that country!

The US visa won't get you into other countries. Your ability to get back to the US after visiting other countries would depend on whether you have a multiple entry visa for the US or not. As long as you have a multiple entry visa that is still valid, you should be able to return. But basically, it's like you returned home and decided to come back to the US. The new entry would be independent of the original entry.

Yes,you're allowed to travel to another
country from the U.S. but you must be qualified to enter that country either through a visa or special arrangement between your country of origin & that country.in case you want to Re-enter the
U.S.,you should have enough time on your
U.S.visa otherwise,you must apply for another new visa.
good luck.

n o

Not unless you've brought the visa for that country from your home country.