I was in Israel a few years ago and I was SO glad I started taking probiotic tablets a week before and continued to take them twice a day while in the middle east. I was the only one in our group that did not get any kind of intestinal problem. In Norway we have pills called Idoform.
When you barter for things remember that the real barter begins when you get them down to 50% of the price! It is after that the fun begins. Don't show the palm of your hand (as in the gesture for stop) or the sole of your shoe in Arab establishments. If you enter an Arab store "and accept the offer of a cup of tea" you are EXPECTED TO BUY SOMETHING!
Some of the best deals may be on spices that are really expensive here. Saffron, cardamom, nutmeg etc is a great price there. Be sure to seal them in a plastic container or jar in your suitcase. Plastic bags don't hold in the aroma.
Take your wet wipes, tissue packs (to use as toilet tissue), antiseptic gel for toilets and your hands after... Be sure to pack anti-diarrhea meds- (Imodium) as well as anti-nausea meds, anti-itch creams. Health care and drug stores in Israel - very good.. Egypt, not so good, Jordan, I have no idea.
The biggest risk factor is not drinking enough water! :thumbdown: 1 liter/ hour is a necessity, if you wait until you feel thirsty it is too late! Don't under estimate the impact of dehydration.
Geeze, I feel like a worry wart, but these are little things that can make a real difference in having a good time.
Hugs