Since
@kennycro@@aol.com was nice enough to grab me, I'll toss in my two cents.
Note that excess gas and diarrhea are actually from two different causes (broadly speaking).
The gas is usually a result of too much sugar, starch, or protein making it through the small intestine and into the colon. The colon doesn't absorb much in the way of nutrients, just water, so gut bacteria in the colon will go wild with all the extra (easy to digest) food you're giving them. As a waste product, they produce gas, and that gas makes you feel bloated until you, ya know, get rid of it (public enemy number one style). Those bacteria also digest fiber, but not as quickly, so most folks don't have fiber-related bloating issues unless they're eating quite a lot of it. That said, high loads of fiber can interfere with full digestion, so a high fiber meal can "carry" carbs and protein to the colon.
Diet-related diarrhea is usually due to the colon not absorbing enough water out of the liquid coming from the small intestine. If you abruptly stop eating fiber (a la carnivore, or something similar), then you're colon has to step up it's water absorption game to absorb the water that would normally be bound up by fiber. This can cause watery stool for a week or two while the colon is adjusting. This isn't a bad thing or a big deal (as long as you have reliable access to the john), but I would hesitate to call it "normal and healthy". Being terrified of sneezing is no fun
. If you're taking in a lot of electrolyte or have a lot of undigested nutrients in the colon, that can "hold on to water" via osmosis, and make it very difficult for the colon to absorb it. This means that taking in more nutrients than you can digest can cause both bloating and watery stool, culminating in explosive diarrhea. So that's neat.
Fat can also cause some osmotic diarrhea, but usually the diarrhea related to excess fat consumption (#ketoallday) is just because fat is liquid at body temp, and fat that get through the small intestine unabsorbed will continue on through the colon.
To bring things back to the OP, his bloating is likely due to him taking in more starch/sugar than his small intestine can absorb, which means he's feeding his gas-producing gut bacteria all sorts of goodies. This is another situation where the body should be able to adapt, so
@steve-in-kville can either A) cut back on the smoothies to the amount that his small intestine is actually absorbing, and slowly increase from there, or B) just keeping blimping it up until his body gets itself sorted out. Neither is a "bad" option, but there is a financial argument for option A, since option B means you're buying food that's not actually feeding you. You could also take in the same amount of stuff, but spread it out over more smoothies throughout the day.
I'm not convince that main-lining plants is all it's cracked up to be anyways, but that's another discussion entirely.