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Fibre for Haemorrhoid Complications

Systematic review

Fibre is usually recommended as one way of treating haemorrhoids, to minimise constipation and the prolonged straining associated with constipation. Like many recommendations with a long shelf life, there is lots of experience behind this, but few of us could quote the trial evidence. A systematic review [1] tells us both that there is minimal evidence from good quality trials, and that such evidence that exists suggests that fibre is helpful.

Systematic review

Searching (to early 2005) was excellent. As well as searching many databases, authors contacted companies, experts, and authors. Included studies had to be randomised studies of fibre of any type or dose versus placebo or no therapy in patients with symptomatic haemorrhoids. Outcomes sought included symptomatic improvement, bleeding, prolapse, and surgery, together with any adverse events.


Although seven trials were included, only four provided information on outcomes and were unambiguously randomised and double blind. Most patients presented with rectal bleeding as their main complaint. The duration of studies was up to 12 weeks, and three different forms of fibre were used in the four trials. The number of patients was small, at about 250 in total.

Results for the main outcomes are shown in Table 1. The number of patients with persisting symptoms (Figure 1) or bleeding was reduced by half with fibre compared with placebo (relative risk 0.5; 95% confidence interval 0.4 to 0.7). With placebo, 46% of patients still had persisting symptoms at the end of the study, while with fibre this was reduced to 23%. The number needed to treat for one more patient to be free of symptoms or bleeding was about 4, both for persistence of symptoms or rectal bleeding. There was no difference in prolapse. There was no significant increase in mild adverse events.

Table 1: Outcomes from systematic review of randomised trials of fibre versus placebo in patients with established troublesome, mostly bleeding, haemorrhoids

Number of
Percent with outcome
Relative risk
(95% CI)
Persisting symptoms
0.5 (0.4 to 0.7)
4.4 (2.9 to 8.7)
0.5 (0.4 to 0.7)
3.9 (2.7 to 7.2)
0.8 (0.6 to 1.3)
not calculated

Figure 1: Persistence of symptoms in patients with established haemorrhoids treated with fibre or placebo


Fibre is generally used in patients with less severe haemorrhoids. The evidence we have is reasonable, though a concern is that the largest of the trials is the one with the smallest effect (Figure 1). The dearth of trials and patients means we can only be reasonably sure that fibre is helping, despite the statistical significance.

There are considerable unknowns. We do not know how big the effect of fibre is, the best fibre product, nor the most appropriate dose of that product. Nor can we be sure, with this number of patients, about common adverse events, and especially about rare, but possibly more serious, adverse events. What we know best is what we do not know.

We do, though, have a wealth of clinical experience to draw on, and in this case that wealth of clinical experience from clinical practice is supported by limited evidence from clinical trials. Getting more fibre or whole grain into the diet is an important healthy living message, and not just for constipation and haemorrhoids. Eating more than four servings of whole grain every week reduces rates of some cancers by 20%-50% (Bandolier 53). A major health message.


  1. P Alonso-Coello et al. Fiber for the treatment of hemorrhoids complications: a systematic review and meta-analysis. American Journal of Gastroenterology 2006 101: 181-188.

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