Answer:
Fiber is defined as material made by plants that is not
digested by the human gastrointestinal tract. Fiber is one of the mainstays in
the treatment of constipation
though it also may have additional uses such as the treatment of diverticular disease of
the colon. Many types of fiber bind to water and
keep the water within the intestine. The fiber and water adds bulk
(volume) to the stool, and the water softens the stool. Increased gas (flatulence)
is a common side effect of high-fiber diets. The gas occurs because bacteria
within the colon, unlike the intestine of humans, are capable of digesting fiber to a
small extent. The bacteria produce gas as a by-product of their digestion of fiber.
There are different sources of fiber, and the type of fiber varies from source
to source. Some types of fiber are digested to a greater extent by colonic
bacteria than other types of fiber. The better-digested fiber produces more gas.
All fibers, no matter their source, can cause flatulence;
however, since bacteria vary in their ability to digest different types of
fiber, different sources of fiber may produce different amounts of gas. To
complicate the situation, the ability of bacteria to digest one type of fiber
can vary from individual to individual. This makes the selection of the best
type of fiber for each individual (i.e., a fiber that improves the quality of
the stool without causing flatulence) more difficult. The choice becomes a
matter of trial and error.
Types of fiber can be categorized in several ways,
for example, by their source. The most common natural sources of fiber include
fruits and vegetables as well as wheat or oat bran. These fibers are
most likely to cause flatulence. Fibers used medicinally to treat
constipation include psyllium seed, synthetic cellulose (methyl cellulose),
and calcium polycarbophil. (A lesser known source is an extract of malt;
however, this extract may soften stools in ways other than by increasing
fiber.) Psyllium and methyl cellulose (and probably calcium polycarbophil)
do not increase the production of gas; however, they still may result in the
sensation of bloating. This may be due to an effect of these fibers that
slows the transit of gas through the intestine.
The
different sources of fiber should be tried one by
one. The
fiber should be started at a low dose. The dose should be increased every 1-2
weeks until either the desired effect on the stool is obtained or troublesome bloating or
flatulence (or other gastrointestinal symptoms) supercedes. (Fiber does not work overnight!)
If bloating or flatulence occurs, the dose of fiber can be reduced
for a few weeks, and then the higher dose can be re-instituted. (It generally is
said that the amount of bloating or gas that is produced by fiber decreases
when it is ingested for a prolonged period of time; however, this has
never been carefully studied or proven.) If bloating or flatulence remains a problem
and prevents the dose of fiber from being raised to a level that
affects the stool satisfactorily, it is time to try a different source of fiber.
When using
increasing amounts of fiber, it is recommended that increasing amounts of water
be ingested, presumably to provide water for the fiber to bind and prevent
"hardening" of the fiber and obstruction of the intestine. This is simple and
reasonable advice; however, it has never been shown that the amount of ingested
water has any beneficial effect. (There is a lot of water in the normal
intestine, and extra water is just absorbed and excreted in the
urine.) Despite the lack of demonstrated benefit, it probably is a good idea not to become dehydrated while taking fiber supplements.
Thank you for your question.
Digestion RSS