Bower has made 52 appearances for Warriors in all competitions since joining from Leicester Tigers in 2014.
Details of the length of the 26-year-old's new contract at Sixways have not been disclosed.
"He always gives everything he's got and I've been thoroughly impressed with his attitude and his performance," director of rugby Gary Gold said.

In a tactical race, 24-year-old English held off European Indoor silver medallist Andreas Bube of Denmark to win in 1:49.02.
Dublin runner Brian Gregan won the 400m while City of Lisburn club's Amy Foster was second in the 100m in 11.70.
Ireland's eighth place in Vaasa meant they were 20th overall in Europe.
That is their lowest placing in the biannual event since 2011.
The League One event was won by Sweden who were promoted to the Super League alongside hosts Finland and Switzerland.

Mr Hammond dismissed reports of angry rows between the two as "tittle tattle" although he jokingly acknowledged he occasionally swore.
Mrs May said she was "focused on 8 June".
Mr Hammond and Mrs May were speaking at a press conference they arranged to attack Labour's election manifesto.
Taking questions from journalists after claiming Labour's pledges created a multibillion pound "black hole", they were asked about reports of a rift between their offices since the U-turn over National Insurance in March's Budget.
Asked by BBC political editor Laura Kuenssberg whether they would "still be neighbours" after the general election - the chancellor's official residence is 11 Downing Street - Mrs May said: "I think it's true to say that the chancellor and I and every other member of my team are focused on 8 June."
She was also pressed to give an endorsement of her chancellor, replying that she was "very happy to do so".
"As Philip says, we have worked together for many years," she said. "Longer than we would care to identify - that's an age-related comment, nothing else."
Mr Hammond said he and Mrs May worked "very closely together".
He added: "What I candidly admitted - and my family will confirm this - is I do occasionally swear."
This morning the chancellor's admission that he sometimes swears, as he sought to play down reports of rows with Team May, won't have helped.
Nor will the PM twice refusing to say he would still be her chancellor if she is elected.
She did, at the third time of asking give him her endorsement.
And moving him after the election if the Tories win would be a dramatic and risky move.
But this morning's excursion won't have helped relations between the two addresses.
Read Laura's blog

A passer-by found the man, who has not been named but was in his 30s, off Promenade Street in Heywood at about 23:25 GMT on Thursday.
He was pronounced dead at the scene and officers are treating the death as suspicious.
A post-mortem examination is due to take place and officers have asked for any witnesses to contact them.
Worcester Warriors loose-head prop Ryan Bower has signed a new contract with the Premiership club.
[NEXT_CONCEPT]
Donegal's Mark English won the 800 metres as Ireland finished eighth in League One of the European Team Championships in Finland.
[NEXT_CONCEPT]
Prime Minister Theresa May has laughed off questions about whether Chancellor Philip Hammond would still be in place after the general election.
[NEXT_CONCEPT]
Police have launched an investigation after the body of man was found in an alleyway in Rochdale.