long_beach_husband, If a cup or more of fluid suddenly gush out of your wife's mouth, you will most certainly not argue that it is her saliva glands that suddenly produced that much saliva all at once. It must clearly come from the closest fluid store connected to her mouth - her stomach.
The same goes for female gushing. It is physiologically impossible for that much fluid to be produced out of thin air in such a short period of time anywhere in the human body. If it is anything more than a teaspoon or two of fluid, it is from her bladder.
Thanks to modern radiological studies (MRI, CAT and ultrasound) of couples having sex and masturbating women, the bladder can be seen filling up in a very short period of time during arousal, there is only one question left: is it urine, another fluid or a mixture of fluids. No other fluid or fluid store can be observed anywhere in her pelvic region, only in her bladder.
Even Dr Beverly Whipple, which are widely credited with the naming of the G-Spot and much of the hype around female ejaculation research was a co-author of a paper on orgasms in Feb 2008 with the following statement:
"Stimulation of the hypogastric nerve probably occurs also during uterine contractions at orgasm and during stimulation of the G Spot, a component of which are the Skeneâs glands, considered to be a homologue in women of the prostate gland. Ejaculation of a fluid (usually 3â5 ml â approximately one teaspoonful) from the urethra in women, which is chemically different from urine (Belzer et al., 1984), is reported to originate from the female prostate gland (Zaviacic, 1999)."
Dr Perry, which was the other researcher with Dr Whipple postulated the 'Beer Piss Theory' stating that the fluid is coming from the bladder but might be different in composition to urine (or at the very least a clear and diluted urine.
"The most controversial aspect of the discoveries about female ejaculation concerns the volume of fluids sometimes claimed, or even photographed and videotaped. Many professionals have been unable to find these large-volume ejaculations credible, especially in the light of the relatively small mass of the glands that comprise the Skene's glands (also known as paraurethral glands or female prostate). At the very least, they argue, the female glands should not be credited with producing any more, and probably less, fluid than the corresponding male glands."
. . . . . . .
"in every case, the amount of ejaculation would best be described as "less than a thimble-full", sometimes MUCH less, and never the copious amounts shown in recent films."
. . . . .
"One hypothesis is that women are being trained to release "beer piss", either in addition to OR instead of ejaculation.
In summary, there now appears to be three kinds of fluid that women may expel during sexual activity:
(1) ordinary urination (large volume, yellow color)
(2) female ejaculation (small volume, colorless)
(3) "beer piss" (large volume, also colorless)
And combining (2) and (3) leads to a fourth option:
(4) ejaculation mixed with "beer piss" (large volume, colorless)
The proof - provided by Schubach's research - that women can produce "beer piss" (just like men) goes a long way towards resolving the skepticism that many scientists had about female ejaculation in the early 1980s. After all, most skeptics did not challenge the presence of acid phosphatase and glucose in ejaculation specimens, but they did reject the large volumes of fluid reported"
There is a reason why research into female gushing was abandoned in the late 1990's without any conclusions. The theory that gushing was just an extreme form of female ejaculation could not be proven.
So it does not matter who or what you like to believe about female gushing, the fluid can only come from her bladder. The only question remaining is how does it get there (in other words, does arousal change the composition and process in the liver and bladder). There seems to be some indication that it does, as you yourself state here.
Does this make her orgasms, your enjoyment of her sexual response any less or any less valid? Definitely not and it should not do so. Gushing is connected to intense sexual pleasure and should be enjoyed by both partners.
Take care!