The medical condition arose after he damaged a disc during his swim along the River Thames.
The 42-year-old has been told by doctors that he needs to rest after going into hospital this week to fix a disc he tore during a charity swim in 2011.
"Unfortunately the operation on my back is long overdue. The doctors have ordered me to rest for the remainder of the year so I can recover," he told mirror.co.uk.
He has also apologised to fans for postponing his "World of Walliams" book event, scheduled to be held at London's Palace Theatre Dec 7, until March next year.
Walliams, who is married to 29-year-old model Lara Stone, has been on medication for back pain since his gruelling 140-mile swim along the River Thames which raised two million pounds for charity Sports Relief.
--IANS (Posted on 28-11-2013)