BendingOak wrote:The majority of the weight loss would be from water loss through dehydration/perspiration.
Where would that water be coming from?
Every cell in your body depends on water, not just muscle cells and fat cells.
As you dehydrate, water from your entire body lessens. At first, you feel thirsty, have decreased urine output and maybe a headache or dizzyness. Then you may get lethargic and even have seizures. As dehydration worsens, your blood thickens and gets more difficult to pump causing low blood pressure. As a result your respiration increases to compensate for less oxygen in the blood.
If you are still unfortunate enough to have no water, your lips, tongue and mucous linings of the nose dry out and start to crack and bleed. The lining of your stomach dries out and you experience dry heaves. Your eyes recede into the back of your head and appear sunken and your skin becomes dry and scaly. Urine (if you have any at this point) becomes concentrated and actually burns the bladder.
Of course, without sweat to cool your body, your temperature starts to climb, your brain cells dry out and you go into convulsions. If you are still alive at this point, you will more than likely die of organ failure - or hope to soon.
In Ford's case, the dysentary would most likely cause only rudimentary symptoms such as physical exhaustion, weakness or possibly collapse. Since he was in a movie and there were people all around, the fluids were more than likely plentiful and he would only be battling the disease itself. People who start low-carb diets commonly shed 5lbs. of water weight in a matter of a few days.
There is an excellent article (I think in Time Magazine) that describes the perils of the undocumented immigrants coming from Mexico and the terrors that they encounter to achieve the American Dream. It describes the dehydration process in horrifying detail. My Mom also suffered from dehydration and I see a lot of the early symptoms in folks while I am hiking. Dehydration is scary.
(Edited on 10/11/2006 at 8:34am for spelling)
I'm never going to come to Italy to visit you now! 
