Your welcome Jackie, although I dont feel I have been much help.
I've been to Sharm 3 times over the last 4 years, stayed at the Rennaisance Golden View Beach Resort, The Crowne Plaza, both of which were Bed and Breakfast so we ate in a variety of restaurants including the hotels and this year I stayed at The Red Sea Holiday Village which is an All Inclusive so only ate there.
Each time we have all been OK (probably jinxed it now) - family of 4 - apart from last time when just me had a slight tummy upset for about two to three hours, nothing that you would bother getting Antinal for though.
Also we have never bothered with pro-biotics, always had ice in drinks and eaten plain salads, but tried to make sure food we picked is always hot. I take the hand gel stuff and then forget to use it.
I did put air c o n on for a few hours before we went to bed then turn it off over night as people say that can cause problems, but who knows really, but that was in Spring and is easier said than done in the height of summer.
I really do think it's a bit the luck of the draw really. Loads of people go and don't get poorly. Just take sensible precuations and try not to worry, although I am sure it is more of a concern if you have been poorly recently.
Take Care, Doe