I know this is a very old post..... but I thought I'd do some research. ONe of my friends fainted on descent into brisbane early last year. She actually lost control of her bladder as well. The people next to her did not notice (or if they did they didn't tell anyone)
ANyway she flew to other australian destinations throughout the year with no problems, but then flew to brisbane and on descent she started to feel very hot, ill and faint again, but this time she did not pass out.
Both times she flew on 737 aircraft. Does anyone know why this could happen? She had not been drinking and her health was fine.