Fick ett intressant mail från en av mina läsare angående kostfiber och reduktion eller total eliminering av dessa för att minska symtom från magen. För egen del är det där lite av ett vågspel. Det gäller att inte få FÖR mycket fibrer men inte heller FÖR lite och dessutom är det av största vikt att det är rätt typ av fiber. De där som inte retar för mycket och inte bildar en massa gas.
För vissa av oss är det a och o att utesluta fibrer för att få en välfungerande tarm och för andra av oss behövs de - i lagom dos. Den där hetsen kring kostfiber som var för några år sedan har skördat sina offer och forskningen har väl snarast visat att ett för högt intag ställer till mer än vad det hjälper för oss med känsliga magar. Annat var det för några år sedan när ökat intag av fibrer var lösningen på all världens magproblem.
Här kommer i alla fall studien jag fick ta del av och som kan vara intressant att läsa även för den som ännu inte testat att utesluta eller minimera fibrer ur sin kost. Att FODMAP funkar och/eller minskar symtom från känsliga magar är väl mer regel än undantag idag och man hör talas om det i princip överallt. Detta är ett lite annat sätt tillvägagångssätt men precis som FODMAP väl värt att testa.
Artikeln kommer från World Journal of Gastroenterology
Stopping or reducing dietary fiber intake reduces
constipation and its associated symptoms
Kok-Sun Ho, Charmaine You Mei Tan, Muhd Ashik Mohd Daud, Francis Seow-Choen
Kok-Sun Ho, Charmaine You Mei Tan, Muhd Ashik Mohd
Daud, Francis Seow-Choen, Seow-Choen Colorectal Surgery
PLC, Singapore 238859, Singapore
Author contributions: Seow-Choen F designed the research;
Tan CYM and Mohd Daud MA were responsible for data collection
and analysis; Ho KS and Seow-Choen F wrote the paper.
Correspondence to: Francis Seow-Choen, MBBS, FRCSEd,
FAMS, Seow-Choen Colorectal Surgery PLC, 290 Orchard
Road, The Paragon No. 06-06, Singapore 238859,
Singapore. seowchoen@colorectalcentre.com
Telephone: +65-67386887 Fax: +65-67383448
Received: January 4, 2012 Revised: April 18, 2012
Accepted: April 22, 2012
Published online: September 7, 2012
Abstract
AIM: To investigate the effect of reducing dietary fiber
on patients with idiopathic constipation.
METHODS: Sixty-three cases of idiopathic constipation
presenting between May 2008 and May 2010 were
enrolled into the study after colonoscopy excluded an
organic cause of the constipation. Patients with previous
colon surgery or a medical cause of their constipation
were excluded. All patients were given an explanation
on the role of fiber in the gastrointestinal tract.
They were then asked to go on a no fiber diet for 2
wk. Thereafter, they were asked to reduce the amount
of dietary fiber intake to a level that they found acceptable.
Dietary fiber intake, symptoms of constipation,
difficulty in evacuation of stools, anal bleeding,
abdominal bloating or abdominal pain were recorded
at 1 and 6 mo.
RESULTS: The median age of the patients (16 male, 47
female) was 47 years (range, 20-80 years). At 6 mo, 41
patients remained on a no fiber diet, 16 on a reduced fiber
diet, and 6 resumed their high fiber diet for religious
or personal reasons. Patients who stopped or reduced
dietary fiber had significant improvement in their symptoms
while those who continued on a high fiber diet
had no change. Of those who stopped fiber completely,
the bowel frequency increased from one motion in 3.75
d (± 1.59 d) to one motion in 1.0 d (± 0.0 d) (P < 0.001);
those with reduced fiber intake had increased bowel frequency
from a mean of one motion per 4.19 d (± 2.09 d)
to one motion per 1.9 d (± 1.21 d) on a reduced fiber
diet (P < 0.001); those who remained on a high fiber
diet continued to have a mean of one motion per 6.83
d (± 1.03 d) before and after consultation. For no fiber,
reduced fiber and high fiber groups, respectively, symptoms
of bloating were present in 0%, 31.3% and 100%
(P < 0.001) and straining to pass stools occurred in 0%,
43.8% and 100% (P < 0.001).
CONCLUSION: Idiopathic constipation and its associated
symptoms can be effectively reduced by stopping
or even lowering the intake of dietary fiber.
© 2012 Baishideng. All rights reserved.
Key words: Dietary fiber; Constipation; Chronic idiopathic
constipation; Abdominal bloating
Peer reviewers: Dr. Jit Fong Lim, Gleneagles Hospital
Singapore, 6 Napier Road, No. 09-09, Gleneagles Medical
Centre, Singapore 258499, Singapore; Poh-Koon Koh, Professor,
Capstone Colorectal Surgery Centre, Mt Elizabeth Hospital, 3
Mount Elizabeth, No.07-08, Singapore 238499, Singapore
Ho KS, Tan CYM, Mohd Daud MA, Seow-Choen F. Stopping
or reducing dietary fiber intake reduces constipation
and its associated symptoms. World J Gastroenterol 2012;
18(33): 4593-4596 Available from: URL: http://www.wjgnet.
com/1007-9327/full/v18/i33/4593.htm DOI: http://dx.doi.
org/10.3748/wjg.v18.i33.4593
INTRODUCTION
Lack of fiber in the diet was first postulated in 1971
World J Gastroenterol 2012 September 7; 18(33): 4593-4596
ISSN 1007-9327 (print) ISSN 2219-2840 (online)
© 2012 Baishideng. All rights reserved.
Online Submissions: http://www.wjgnet.com/esps/
wjg@wjgnet.com
doi:10.3748/wjg.v18.i33.4593
WJG|www.wjgnet.com 4593 September 7, 2012|Volume 18|Issue 33|
Ho KS et al.
Dietary fiber and constipation
as the cause of diseases such as diverticulosis, hemorrhoids
and colorectal cancer[1]. Since then, partly due to
widespread media publicity, it is now widely accepted
that dietary fiber is a necessary component of a healthy
diet and is required for normal bowel movement[2-5]. It
is popularly used in the management of constipation
by the public and by many doctors. Insoluble fiber is
known to increase stool weight and decrease colonic
transit time[6,7]. Fiber is said to aid in water retention in
the colon and results in stools that are less dry and easier
to evacuate. However, the reality is that stool moisture
content remains at 70%-75% regardless of the amount
of fiber and water consumed[7,8].
There is recent evidence that low fiber intake does
not equate to constipation[9]. Patients with chronic constipation
also have similar fiber intake to controls[10-13].
Patients with chronic constipation may also have worsening
symptoms when dietary fiber intake is increased[14].
Another study found that lactulose was more effective in
easing constipation when compared with fiber[15].
It has also been our experience that many patients
with constipation are already consuming a large amount
of fiber before they seek medical attention.
We therefore carried out a prospective longitudinal
case study to investigate the effect of decreasing dietary
fiber in patients with idiopathic constipation.
MATERIALS AND METHODS
Constipation was defined clinically in patients who presented
either with symptoms of straining to expel bulky
large stools or a bowel frequency of less than one motion
per 3 d over a period of at least 3 mo. Patients who
presented to the clinic with symptoms of constipation,
abdominal distension, pain or bloating, difficulty in evacuation
with or without symptoms of rectal bleeding were
considered for the study. For the purpose of this study,
we did not distinguish between slow colonic transit type
or obstructed defecation type of constipation nor did
we attempt to classify the patients according to irritable
bowel syndrome subtypes. All the patients underwent
colonoscopy to exclude colonic lesions. Patients who had
colorectal cancer, previous colonic surgery, melanosis coli
or thyroid disorders were excluded. Patients with anal
conditions such as severe prolapsed hemorrhoids, chronic
anal fissure or any other condition that required surgery
were also excluded.
Sixty-three consecutive patients after normal colonoscopy
were enrolled into the study from May 2008 to May
2010. Each patient was to act as their own control. The
physiology of the gastrointestinal tract and the bulking
effects of dietary fiber were explained to the patients[16,17].
Patients were then instructed to completely stop their intake
of dietary fiber, including vegetables, cereals, fruits,
wholemeal bread and brown rice for 2 wk. Those who
were vegetarians were asked to eat white rice instead of
unpolished rice, white bread instead of whole meal bread,
and to take processed bean products for protein. They
were to continue their normal quantities of carbohydrates
and proteins. Sieved fruit juices and clear vegetable soups
were allowed. Patients were instructed not to take any laxatives
during these 2 wk. After 2 wk, patients were asked
to continue on with as little fiber in their diet as they were
comfortable with for the long term. Patients were followed
up at 1 mo and 6 mo intervals and final results were
analyzed at 6 mo.
Data collected included age, sex, general dietary fiber intake,
symptoms of constipation, difficulty in evacuation of
stools, anal bleeding, abdominal bloating or abdominal pain.
Constipation was recorded as the interval in days between
bowel movements. Difficulty in evacuation was a subjective
measure and patients were asked to choose from one of 3
degrees (no straining, occasional or moderate straining and
severe straining or straining most of the time).
Statistical analysis
All data was entered into a secured database, and accessed
only by the authors. The paired samples t test was
performed using SPSS for Windows (SPSS Inc., Chicago,
United States), version 17.0 on an IBM personal
computer. Results are expressed as mean ± SD.
RESULTS
There were 16 males (25.6%) and 47 (74.4%) females, median
age 47 years (range, 20-80 years) included in the study.
At the commencement of the study, all patients were already
on a high fiber diet or taking fiber supplements. After
2 wk of a no fiber diet, patients were asked to continue
on as little fiber in the diet as they were able to follow if
this were to give them relief from their symptoms.
At 6 mo, 41 patients continued on a no fiber diet and
16 were on a reduced fiber diet. The remaining 6 patients
continued on a high fiber diet for various reasons
including being vegetarians or inability to stop consuming
dietary fiber for religious or personal reasons.
The median age of patients who stayed on a no fiber
diet was 46 years (range, 21-80 years), on a reduced fiber
diet was 45 years (range, 20-65 years) and on a high fiber
diet was 59 years (range, 28-75 years). There was no statistical
significant difference in age between the 3 groups.
There was also no statistical difference in sex between
the 3 groups (Table 1).
At 6 mo follow-up, the interval between bowel movements
decreased with the reduction in fiber intake (P <
0.001). Forty one patients who completely stopped fiber
intake had their bowel frequency increased from one
motion in 3.75 d (± 1.59 d) to one motion in 1.0 d (± 0.00
d) (P < 0.001). Of 16 patients who reduced their dietary
fiber intake, 12 patients had daily bowel movement, 3
had one bowel movement every 2 to 3 d and one had a
bowel movement every 4 to 6 d, giving one motion per
1.9 d (± 1.21 d) on a reduced fiber diet compared with
1 motion per 4.19 d (± 2.09 d) on a high fiber diet (P <
0.001). There was no change in the frequency of bowel
movement for patients who continued with high dietary
fiber intake, with one motion per 6.83 d (± 1.03 d) before
and after consultation (P = 1.00).
WJG|www.wjgnet.com 4594 September 7, 2012|Volume 18|Issue 33|
There was also a difference between the groups in
the proportion of patients with associated symptoms.
For symptoms of bloating, all of those on a high fiber
diet continued to be symptomatic, while only 31.3% in
the reduced fiber group and none of the no fiber group
had symptoms (0%, P < 0.001) (Table 2).
With regards to straining, all those on a no fiber no
longer had to strain to pass stools. Of those who reduced
dietary fiber, 7 of 16 showed improvement while
the symptoms remain unchanged in those who remained
on a high fiber diet (P < 0.001 between groups).
Symptoms of abdominal pain only improved in patients
who stopped fiber completely while those who
continued on a high fiber diet or reduced fiber diet did
not show any improvement (Table 2). In addition, those
on a no dietary fiber diet no longer had symptoms of anal
bleeding.
DISCUSSION
This study has confirmed that the previous strongly-held
belief that the application of dietary fiber to help constipation
is but a myth. Our study shows a very strong
correlation between improving constipation and its associated
symptoms after stopping dietary fiber intake.
However whilst there was no significant difference between
the mean age of the 3 groups with different postconsultation
dietary fiber intake, older patients seemed
less likely to stop dietary fiber, although this did not reach
significance. We did not survey the actual reasons for resuming
dietary fiber. The clinical impression during consultation
however was that some of these patients were
vegetarians, some felt uneasy not eating any fiber, whilst
others could not completely discontinue fiber due to constant
media and peer pressure to increase dietary fiber.
Constipation is often mistaken by the layman as the
state of not passing stool, with the subsequent false notion
that making more feces will allow easier defecation.
In truth, constipation refers to the difficulty in evacuating
a rectum packed with feces, and easier defecation
cannot possibly be affected by increasing dietary fiber
which increases bulky feces. In this paper, we looked at
constipation both as the number of days before each
motion as well as the ease of defecation.
It is well known that increasing dietary fiber increases
fecal bulk and volume. Therefore in patients
where there is already difficulty in expelling large fecal
boluses through the anal sphincter, it is illogical to actually
expect that bigger or more feces will ameliorate this
problem. More and bulkier fecal matter can only aggravate
the difficulty by making the stools even bigger and
bulkier. Several reviews and a meta-analysis had already
shown that dietary fiber does not improve constipation
in patients with irritable bowel diseases[18-21].
The role of dietary fiber in constipation is analogous
to cars in traffic congestion. The only way to alleviate
slow traffic would be to decrease the number of cars
and to evacuate the remaining cars quickly. Should we
add more cars, the congestion would only be worsened.
Similarly, in patients with idiopathic constipation and a
colon packed with feces, reduction in dietary fiber would
reduce fecal bulk and volume and make evacuation of
the smaller and thinner feces easier. Adding dietary fiber
would only add to the bulk and volume and thus make
evacuation even more difficult.
Whilst it is often stated in physiology textbooks that
bulking agents improve peristalsis, there is no proof of
this in practice nor experimentally. Regardless of the
food ingested, small intestinal and right mid colonic contents
are fluid and all ingestible dietary fiber is suspended
therein. Dietary fiber, therefore, cannot act as solid boluses
for the initiation of peristalsis. In fact, dietary fiber
had been shown to retard peristalsis and hold up gaseous
expulsion in human experiments[22].
Dietary fiber is also associated with increased bloatedness
and abdominal discomfort[22]. Insoluble fiber was reported
to worsen the clinical outcome of abdominal pain
and constipation[18-20]. In our recent study, patients who
followed a diet with no or less dietary fiber intake showed
a significant improvement, not just in their constipation,
WJG|www.wjgnet.com 4595 September 7, 2012|Volume 18|Issue 33|
Variable General (n = 63) No fiber (n = 41) P value Reduced fiber (n = 16) P value High fiber (n = 6) P value
Age (yr), mean (range) 47 (20-80) 46 (21-80) 0.864 45 (20-65) 0.459 59 (28-75) 0.052
Sex1 n (%) 16 (25.4) 15 (36.6) 0.258 1 (6.25) 0.034 0 (0) < 0.01
Table 1 Age and sex of all patients, segregated by post-consultation dietary fiber intake
1
Numbers of male in each group. Corresponding P values for the age and sex of each category to the overall mean are provided.
Symptom Symptoms at presentation
(n = 63)
High dietary fiber
(n = 6) P value Reduced dietary fiber
(n = 16) P value No dietary fiber
(n = 41) P value
Anal bleeding 31 4 1 4 0.216 0 < 0.001
Constipation 63 6 1 12 0.041 0 < 0.001
Bloatedness 33 6 1 5 0.041 0 < 0.001
Strain in bowel opening 63 6 1 9 0.004 0 < 0.001
Abdominal pain 13 3 1 2 0.164 0 0.012
Table 2 Symptoms at presentation and at 6 mo following change in dietary fiber intake
Ho KS et al. Dietary fiber and constipation
but also in their bloatedness. Patients who completely
stopped consuming dietary fiber no longer suffered from
abdominal bloatedness and pain. These symptoms are
caused by the fermentation of dietary fiber by colonic
bacteria, which produces hydrogen, carbon dioxide and
methane[23]. Gases that are trapped by peristaltic colon
exert pressure on the walls, causing the abdominal pain
experienced by patients. This was previously observed in
a prior study on younger patients, when dietary fiber had
been shown not to be effective in the management of
children with recurrent abdominal pain or bloating[21].
Stools only become well-formed in the sigmoid colon
and rectum and by this time, especially in constipated
subjects, more stools result in more evacuation problems.
It is not logical to increase both the volume and size of
stool in patients with idiopathic constipation and indeed
for anybody with difficulty in passing stools, e.g., due to
anismus or anal spasm from anal stricture, fissure or pelvic
outlet disorders. We have shown that decreasing the
bulk and volume of feces immediately enables the easier
evacuation of smaller and thinner stools through the anal
sphincter mechanism. This eliminates the need to strain
in passing stools, and prevents the tearing of the anal
sphincter and bleeding due to large and bulky fecal loads.
None of our patients experienced anal bleeding or straining
following complete abstinence from dietary fiber.
The results of this study should lead us to reexamine
popular beliefs in benefits of dietary fiber and more
studies should be undertaken to confirm or repudiate
these results.
In conclusion, contrary to popularly held beliefs, reducing
or stopping dietary fiber intake improves constipation
and its associated symptoms.
COMMENTS
Background
It is a widely accepted view that dietary fiber is essential for gut health and to
promote bowel movements. However, most patients with chronic constipation
seen by the authors were already taking high fiber diet with no improvement in
their symptoms.
Research frontiers
The role of dietary fiber in patients with chronic constip is reevaluated.
Innovations and breakthroughs
The authors showed that reducing dietary fiber intake may actually improve
symptoms of chronic constipation.
Applications
This could bring relief to millions of people suffering from chronic constipation in
that reducing their dietary fiber intake may relieve their symptoms and suffering.
Peer review
This paper is a preliminary study looking at the effects of dietary fiber on the
symptoms of constipation on a small cohort of cases. The discussion provided
an overview of the evidence available in the literature on this topic and gave a
fresh perspective on the benefits or harm of excessive dietary fiber. All in all, this
is an interesting preliminary study that warrants publication and further research.
REFERENCES
1 Burkitt DP. Epidemiology of cancer of the colon and rectum.
1971. Dis Colon Rectum 1993; 36: 1071-1082
2 Spinzi G, Amato A, Imperiali G, Lenoci N, Mandelli G,
Paggi S, Radaelli F, Terreni N, Terruzzi V. Constipation in
the elderly: management strategies. Drugs Aging 2009; 26:
469-474
3 Anderson JW, Baird P, Davis RH, Ferreri S, Knudtson M,
Koraym A, Waters V, Williams CL. Health benefits of dietary
fiber. Nutr Rev 2009; 67: 188-205
4 Sturtzel B, Mikulits C, Gisinger C, Elmadfa I. Use of fiber
instead of laxative treatment in a geriatric hospital to improve
the wellbeing of seniors. J Nutr Health Aging 2009; 13:
136-139
5 Gallagher P, O’Mahony D. Constipation in old age. Best
Pract Res Clin Gastroenterol 2009; 23: 875-887
6 Müller-Lissner SA. Effect of wheat bran on weight of stool
and gastrointestinal transit time: a meta analysis. Br Med J
(Clin Res Ed) 1988; 296: 615-617
7 Eastwood MA, Robertson JA, Brydon WG, MacDonald D.
Measurement of water-holding properties of fibre and their
faecal bulking ability in man. Br J Nutr 1983; 50: 539-547
8 Marlett JA, McBurney MI, Slavin JL. Position of the American
Dietetic Association: health implications of dietary fiber.
J Am Diet Assoc 2002; 102: 993-1000
9 de Carvalho EB, Vitolo MR, Gama CM, Lopez FA, Taddei
JA, de Morais MB. Fiber intake, constipation, and overweight
among adolescents living in Sao Paulo City. Nutrition
2006; 22: 744-749
10 Preston DM, Lennard-Jones JE. Severe chronic constipation
of young women: ‘idiopathic slow transit constipation’. Gut
1986; 27: 41-48
11 Anderson AS. Dietary factors in the aetiology and treatment
of constipation during pregnancy. Br J Obstet Gynaecol
1986; 93: 245-249
12 Campbell AJ, Busby WJ, Horwath CC. Factors associated
with constipation in a community based sample of people
aged 70 years and over. J Epidemiol Community Health 1993;
47: 23-26
13 Towers AL, Burgio KL, Locher JL, Merkel IS, Safaeian M,
Wald A. Constipation in the elderly: influence of dietary,
psychological, and physiological factors. J Am Geriatr Soc
1994; 42: 701-706
14 Müller-Lissner SA, Kamm MA, Scarpignato C, Wald A.
Myths and misconceptions about chronic constipation. Am J
Gastroenterol 2005; 100: 232-242
15 Quah HM, Ooi BS, Seow-Choen F, Sng KK, Ho KS. Prospective
randomized crossover trial comparing fibre with lactulose
in the treatment of idiopathic chronic constipation. Tech
Coloproctol 2006; 10: 111-114
16 Chuwa EW, Seow-Choen F. Dietary fibre. Br J Surg 2006; 93:
3-4
17 Tan KY, Seow-Choen F. Fiber and colorectal diseases: separating
fact from fiction. World J Gastroenterol 2007; 13: 4161-4167
18 Lesbros-Pantoflickova D, Michetti P, Fried M, Beglinger C,
Blum AL. Meta-analysis: The treatment of irritable bowel
syndrome. Aliment Pharmacol Ther 2004; 20: 1253-1269
19 Rees G, Davies J, Thompson R, Parker M, Liepins P. Randomised-controlled
trial of a fibre supplement on the symptoms
of irritable bowel syndrome. J R Soc Promot Health
2005; 125: 30-34
20 Bijkerk CJ, Muris JW, Knottnerus JA, Hoes AW, de Wit NJ.
Systematic review: the role of different types of fibre in the
treatment of irritable bowel syndrome. Aliment Pharmacol
Ther 2004; 19: 245-251
21 Huertas-Ceballos A, Logan S, Bennett C, Macarthur C. Dietary
interventions for recurrent abdominal pain (RAP) and
irritable bowel syndrome (IBS) in childhood. Cochrane Database
Syst Rev 2008; (1): CD003019
22 Gonlachanvit S, Coleski R, Owyang C, Hasler W. Inhibitory
actions of a high fibre diet on intestinal gas transit in
healthy volunteers. Gut 2004; 53: 1577-1582
23 Goodlad RA. Dietary fibre and the risk of colorectal cancer.
Gut 2001; 48: 587-589
S- Editor Gou SX L- Editor Cant MR E- Editor Li JY
WJG|www.wjgnet.com 4596 September 7, 2012|Volume 18|Issue 33|
