I did some googling to see what I could find elsewhere on the topic. There is no cut and dry answer out there that I could find, but I did find the following information that tends to suggest that switching drinks isn’t really the problem when you get a hangover. You’ve just had too much to drink. The absorption rates of different types of alcoholic beverages are different. When someone switches drinks, the switch in absorption rates but not drinking rates might cause someone to drink more than they imagined they could handle without becoming sick. See all of the fun reading below about absorption rates and the pyloric valve. I couldn’t have found any of this without your tips. Thanks!
Friday13
From http://goodmedicine.ninemsn.com.au/goodmedicine/Factsheets/db/general/drugs/1173.asp
MIXING YOUR DRINKS MAKES YOU MORE INTOXICATED — FALSE
That’s false, but it could make you sick. All drinks contain different levels of alcohol and it’s alcohol that makes you drunk. Whether it’s the 5.5 percent in a cooler or the 30 percent in a glass of liqueur, it’s how much alcohol, not what type.
From http://216.239.37.100/search?q=cache:gAWctf01xlcJ:www.nrcquincy.navy.mil/medical/myths.html+%2B"pyloric+valve"+%2Bbeer&hl=en&ie=UTF-8
MYTH 5: HANGOVERS ARE CAUSED BY SWITCHING DRINKS.
Hangovers are caused by the amount and the rate, not by the kind of alcohol consumed. While metabolizing alcohol, the liver cannot perform its usual functions, one of which is keeping the blood sugar at normal concentration. The result of this is a state called hypoglycemia, or lower than necessary blood sugar. Symptoms of hypoglycemia are hunger, weakness, nervousness, sweating, headache, and tremor. The change in blood vessels, as mentioned in Myth 3 above, can causes headaches. Lastly, a hangover is actually a "mini -withdraw., When the central nervous system is released from the depressed state, the opposite state develops-feeling edgy and irritable. This effect is known as “rebound.”
From http://216.239.37.100/search?q=cache:BviCL1nMh-4J:userwww.service.emory.edu/~bcmitch/pe101/healthtest3.htm+%2B"pyloric+valve"+%2Bbeer+%2Bliquor&hl=en&ie=UTF-8
the higher the concentration of alcohol, the faster it is absorbed by your digestive tract. As a general rule, beer and wine rare absorbed more slowly than distilled beverages.
carbonated alcoholic beverages are absorbed more rapidly than those with out carbonation because the carbonation relaxes the pyloric valve and allows more of the alcohol to pass on to the small intestine where it is more rapidly absorbed.
the more alcohol you consume the longer absorption takes
if alcohol builds up in the stomach it may become irritated and completely close the pyloric valve. if this irritation continues vomiting may result.