Better out than in. An increase in fibre will cause gassiness and can cause loose stools (because it passes through more readily). This is what is responsible for the blazing saddles scene- you know the one with the baked beans effect???? Baked beans (in fact all pulses) are very high in fibre and have carbohydrates also, ergo the humorous effect. The effect should tend to decrease with your body getting used to it.
Carbohydrates can also lead to gassiness because of the sugars - they basically ferment like beer in your gut and produce gas. Which has to come out some time. I find the combination of sugars and fibre in dried fruit has a particularly pronounced effect that way (very soft, ill formed stools that are actually pretty much chunks of dried fruit partially digested - they just get through too quick) - but I still eat it.
Protein will tend to constipate you and I do find (because I don't eat much meat) that when I do eat meat, I feel all bound up for a few days and I get slight stomach aches that night, like I'm struggling to digest - probably because I'm not used to it.
Basically, the more balanced your diet, the better it should be at your back end.
35kg lost. (November 2005 - October 2006)
15kg gained again (as at October 2010).
Back to the drawing board - Let's do this thing!
"You can't change the winds, but you can change the sails"
"Reach out and take control of what lands in your lap"