Frommer's Medieval Middle East on 10 Ducats A Day

Medieval travelers left behind much practical advice:

But a traveler cannot live on patience alone. For sustenance, Brasca recommended Lombard cheese, cured tongue, biscuits, sugar — and fruit syrup, “because that is what keeps a man alive in extreme heat; and also ginger syrup to settle his stomach if it is upset by too much vomiting.” He does not explain how much vomiting is too much. 

English traveler William Wey, who went to the Holy Land in 1458, prudently added “laxatyvys” to the list, and “a cage for half a dosen of hennys or chekyn to have with yow in the galey, for ye schal have nede unto them meny tymes.”