Chaz Bono. (Fred Prouser/Reuters)

In the new book “Transition: The Story of How I Became a Man,” Bono details his transition from a female named Chastity to a male named Chaz, a process that began in 2009. Bono told Time that he was ready for both the surgery and the media attention that followed. “I reached a point where I was completely comfortable and felt with utter certainty that this was the right thing for me to do, and no matter what came at me, I'd be able to handle it.”

Bono’s journey was also documented in “Becoming Chaz,” the first film in the OWN Documentary Film Club, which he will discuss today with Oprah. “As a man trapped inside a female shell, I was very cut off from the whole world,” Bono says in a preview of the documentary. “And now for the first time, I’m living in my body and it looks the way I want it to.”

The documentary features interviews with Cher, Bono’s mother, who voices some concerns about her child’s transition. “I’m afraid she’s not going to be healthy, I’m afraid it’s too much for her,” Cher said.

Watch a preview of “Becoming Chaz,” which airs tomorrow at 9 p.m. Eastern on OWN: