Yes it would happen within 24 hours of eating shellfish particularly, that's how he realised it was diet related for him. When he was on holiday he ate a meal that contained shellfish and asparagus, the gout was so bad he couldn't walk, it was after that he decided to find out if his gout was triggered by his diet. After cutting out shellfish, asparagus and red meat he was so much better, maybe a food diary would help if it turns out to be gout.