AN EMPTY HOUSE IS BETTER THAN A BAD TENANT
Farts.
Flatus. Wind. Gas. Whatever you call it, everyone does it. It’s a
natural part of life. Don’t hold back. Here, Clare Collins, Professor in
Nutrition and Dietetics, University of Newcastle shares some facts
about flatus (and what happens when you try to hold on) in a piece first
published in The Conversation (Australian edition) entitled “What
Happens When You Hold in a Fart”.
Flatus, farts and breaking wind refer to intestinal gases that
enter the rectum due to the body’s usual gastrointestinal processes of
digestion and metabolism and then leave via the anus. As your body
digests food in the small intestine, components that can’t be broken
down move further along the gastrointestinal tract and eventually into
the large intestine called the colon. Intestinal bacteria break down
some of the contents by fermentation. This process produces gases and
by-products called fatty acids that are reabsorbed and used in metabolic
pathways related to immunity and preventing disease development. Gases
can either be reabsorbed through the gut wall into the circulation and
eventually exhaled through the lungs or excreted via the rectum, as a
fart.
HOW MUCH GAS IS NORMAL? It can be challenging for researchers to
get people to sign up for experiments that measure farts. But
thankfully, ten healthy adults volunteered to have the amount of gas
they passed over a day quantified. In a 24-hour period all the flatus
they expelled was collected via a rectal catheter (ouch). They ate
normally but to ensure a boost in gas production they also had to eat
200 grams (half a large can or 7oz) of baked beans.
The participants produced a median total volume of 705ml (24fl oz) of
gas in 24 hours, but it ranged from 476ml (16fl oz) to 1490ml (50fl oz)
per person. Hydrogen gas was produced in the greatest volume (361ml/12fl
oz over 24 hours), followed by carbon dioxide (68ml over24 hours). Only
three adults produced methane, which ranged from 3ml over 24 hours to
120ml (4fl oz) over 24 hours. The remaining gases, thought to mostly be
nitrogen, contributed about 213ml (7fl oz) over 24 hours. [Imperial
measure conversions rounded.]
Men and women produced
about the same amount of gas and averaged eight flatus episodes
(individual or a series of farts) over 24 hours. The volume varied
between 33ml (1fl oz) and 125ml (4fl oz) per fart, with bigger amounts
of intestinal gas released in the hour after meals. Gas was also
produced while they were asleep, but at half the rate compared to during
the day (median 16ml/½fl oz per hour versus 34ml/1fl oz per hour).
FIBRE
AND FLATUS What happens to intestinal gas production when you put
people on a high-fibre diet? Researchers got ten healthy adult
volunteers to eat their usual diet for seven days while consuming 30
grams (1oz) of psyllium a day as a source of soluble fibre, or not. In
the psyllium week, they were asked to add 10 grams – about one heaped
tablespoon – to each meal. At the end of each week, the participants
were brought into the lab and, in a carefully controlled experiment, had
an intra-rectal catheter inserted to quantify how gas (in terms of gas
volume, pressure and number) moved through the intestine over a couple
of hours. They found the high psyllium-fibre diet led to longer initial
retention of gas, but the volume stayed the same, meaning fewer but
bigger farts.
WHERE DO THE GASES COME FROM? Gas in the
intestines comes from different sources. It can be from swallowing air.
Or from carbon dioxide produced when stomach acid mixes with bicarbonate
in the small intestine. Or gasses can be produced by bacteria that are
located in the large intestine. While these gases are thought to perform
specific tasks that impact on health, producing excessive intestinal
gas can cause bloating, pain, rumbling sounds (borborygmus), belching
and lots of farts.
The smelliest farts are due to
sulphur containing gases. This was confirmed in a study of 16 healthy
adults who were fed pinto beans and lactulose, a non-absorbable
carbohydrate that gets fermented in the colon. The odour intensity of
flatus samples was evaluated by two judges (pity them). The good news
was that in a follow-up experiment, the researchers identified that a
charcoal-lined cushion was able to help quash the smell of the sulphur
gasses.
HOLDING ON TO A FART Ever been in a situation
where passing wind is going to be hugely embarrassing and you’ve had to
hold in a fart? Let’s face it – we all have. Trying to hold it in leads
to a build-up of pressure and major discomfort. A build-up of intestinal
gas can trigger abdominal distension, with some gas reabsorbed into the
circulation and exhaled through your breath. Holding on too long means
the build-up of intestinal gas will eventually escape via an
uncontrollable fart. The research is not clear on whether the rise in
pressure in your rectum increases your chance of developing a condition
called diverticulitis, where small pouches develop in the gut lining and
become inflamed – or whether it doesn’t matter at all.
GI
team: “Where ’ere you be let your farts go free” is what our Dads used
to say and they were right. It’s best for health. Just say “Beg pardon.”
Read more:
