We have an apartment in Egypt and visit regularly. We eat out daily in a variety of places from hotel buffets, to back street Hurghada "restaurants".
Having long term colitis, I tend to have problems on holidays generally,(even in the UK) as any change in my usual diet can be a trigger. HOWEVER, I haven't had any
major problems in Egypt yet, and for the first time on our last visit, it was hubby who managed to wake up one morning feeling distinctly crampy. Forwarned by the forum we had pre-purchased Antinal from the El Gouna Pharmacy (fraction of the price of immodium in boots may I add), he took one (flattish oval and yellow tablet), within half an hour felt considerably better, and the problem had disappeared well before lunchtime!! RESULT!
We have always used handgels (well, to be honest the kids are better at remembering than we are!) either purchased here or in supermarkets in Egypt and I keep a bottle of disinfectant liquid soap in the apartment. The Egyptian money is truly appalling and it's hard to disagree with anyone who claims that it is a viable source of infection.
Given my medical history, the fact that we visit 3-4 times a year, and have kids with us, maybe we have been fortunate in that over the last three years our useage of anti-runny-tummy (can't spell the "D" word!!) tablets has been a single solitary tablet. I can only put it down to keeping well hydrated, wearing hats and basic hygiene as I certainly DO have ice in drinks, eat salads, rice and lots of the things that I probably ought not to - we even clean our teeth in tap water now - and spend hours in the Red Sea to boot. Luck or location ???????