The official Van Halen website says the guitarist went under the knife for “a severe bout of diverticulitis.” While saying “no further surgeries are needed” the message also says “a full recovery is expected within 4-6 months.”

We’ll save you a trip to WebMD. The medical website describes diverticulitis as a “sometimes painful condition that develops when pouches (diverticula) that form in the wall of the colon, part of the large intestine, become inflamed or infected.”

Along with symptoms possibly including stomach pain, bloating, nausea and diarrhea, WebMD says “Doctors aren’t sure” what causes the disease.

Eddie’s medical ailment impacts the band’s planned three shows in Japan, originally scheduled for Nov. 20 & 22 at the Chuo Gymnasium in Osaka and Nov. 27 at the Tokyo Dome. Van Halen’s website says the shows are “currently being rescheduled” and that “the band looks forward to seeing and playing for their fans in 2013.”