I've been sick from eating the 'wrong' foods, and while I am pretty hardy, recall about a day and a half of complete blankness in my room at CBR.
Last December I was struggling with recurring pneumonia, which flared up right at the start of my trip. Spent the first two days barely able to get out of bed (offsite) but did get to see Illuminations from my bed at night!
Moved to POR, and ended up extending my stay to a total of 16 nights. I couldn't lie down at night, so sleeping was tough, and every morning when I stood up I would cough for a good 10-20 minutes.
After two days, a room attendant stopped me outside and asked if I was ok since she heard me coughing each morning... Turns out that she wasn't cleaning my section, but was just concerned!! (Very sweet)
Basically I walked around in a bit of a fog for two weeks, since I couldn't catch my breath much. But at least it was 16 days at WDW!!!