Tiger Woods has had his fourth back operation, and the third in 19 months, as questions over his golfing future continue.

The 41-year-old released a statement late on Thursday night confirming he had an operation to alleviate "ongoing pain in his back and leg" which could keep him on the sidelines for at least another six months.

The 14-time major winner announced on his official website: "The surgery went well, and I'm optimistic this will relieve my back spasms and pain.

"When healed, I look forward to getting back to a normal life, playing with my kids, competing in professional golf and living without the pain I have been battling so long."

Woods has not played competitively since withdrawing from the Dubai Desert Classic at the start of February due to back spasms.

The former world No 1 attempted to return in time for the Masters at Augusta National earlier this month, but said his back rehabilitation did not allow him the time to get "tournament ready".

The statement said he will now rest for several weeks before beginning therapy and treatment, adding that patients typically return to full activity in around six months.

Doctor Richard Guyer, who performed the operation, said: "After he recovers from surgery, he will gradually begin his rehabilitation until he is completely healed.

"Once that's accomplished, his workouts will be geared to allowing him to return to competitive golf."