Guitar great Eddie Van Halen has had emergency surgery for a digestive problem, and could be out of action for up to six months, reports People. The 57-year-old rocker suffered from a severe bout of diverticulitis, which involves an inflammation of the colon. His band Van Halen, which recently released its first album with David Lee Roth in nearly 20 years, has delayed a tour of Japan scheduled for November. Van Halen "looks forward to seeing and playing for their fans in 2013," the band said on its website. (More Eddie Van Halen stories.)