[Marileangorifurnimaluim]

Actually, Gandalf suggested Bilbo would start aging naturally after he gave up the ring. This was mentioned in 'The Shadow of the Past' I believe.

Bilbo was older in Rivendell because Frodo was 33 at the Birthday Party, and was 50 by the time he left the Shire. Bilbo had been 'preserved' at 50 and by the time Frodo came to Rivendell, he had naturally aged to 67. This passage of time is not indicated in the movie.

Gollum had been quite young when he was ensnared. Living with his Grandmother, the importance of Birthday Presents and his 'hanging out' with his friend suggests he may have even been a teenager. His youth makes that story particularly sad.

Gollum aged 78 years after losing the ring, so was in his 80s or 90s during the Quest, but still remarkably strong for his age. Remember, hobbits have slightly longer lifespans than humans. They age slightly slower. Living to 111 is respectable, but not uncommon, rather like living to your nineties. A ninety-year-old Gollum is more like sixty-year-old human. Old, but not infirim.

When the ring was destroyed, everything created with it went up in smoke. Bilbo aged an additional 61 years in a night. That's why he was so very much older only a year later when the hobbits met up with him in Rivendell. Gollum would have gone up in a poof of smoke, aging hundreds of years at once.

He would have died in any case.

-Maril