Review for 10.1186/1471-230X-11-122 (2011)

Reviewer's report
Title:Evaluation of gastrointestinal symptoms in different patient groups using
the visual analogue scale for irritable bowel syndrome (VAS-IBS)
Version: 2Date:25 September 2011
Reviewer: Giovanni Barbara
Reviewer's report:
This is an interesting study evaluating 7 visual analogue scales (VAS) developed
for patients with IBS, including abdominal pain, diarrhea, constipation, bloating
and flatulence, vomiting and nausea, psychological well-being and the intestinal
symptoms’ influence on daily life, in 4 different female populations: 52 healthy
volunteers; 39 patients with IBS; 21 patients with severe dysmotility disorders (16
with enteric dysmotility and 5 with chronic intestinal pseudo-obstruction); 26
patients with primary Sjogren’s syndrome (pSS). The Authors showed that
patients with IBS and severe dysmotility disorders have more severe symptoms
in comparison with healthy controls, but they do not differ from each other in
VAS-IBS symptoms, except for vomiting and nausea. In addition, patients with
pSS have more severe digestive symptoms in comparison with controls, but less
severe symptoms in comparison with patients with IBS or dysmotility disorders.
The present study is interesting, however, there are several flaws that reduce the
quality of the manuscript:
1) Selection criteria for the control group remain elusive. Were these subjects
healthy volunteers, or the group is this group representative of the general
population, as suggested in the Discussion? In case these subjects are healthy
volunteers, the conclusion that in the general population people does not suffer
from gastrointestinal complaints is inappropriate. Indeed, healthy volunteers (who
by definition should not report gastrointestinal complaints), are not representative
of the general population. On the other hand IBS represents a high-prevalent
condition in the general population. In addition, it is not surprising that patients
with IBS and severe dysmotility disorders have more severe digestive symptoms
than healthy subjects.
2) In the present study, results showed that patients with IBS scored their
symptoms as severe as those of patients with severe dismotility disorders. This is
not in line with recent reports showing that severe dysmotility is associated with
more severe symptoms as compared with IBS (Cogliandro et al
Neurogastroenterol Motil 2011). This apparent lack of significance may depend
by the small sample size of the present study, hence a likely type II error. In
addition, a bias of selection of patients with IBS may explain these unexpected
results. Patients with IBS referred to a tertiary gastrointestinal centre may present
more severe symptoms in comparison with primary care or in community
patients. For example, IBS female patients seen in referral centres versus
primary care are a highly selected group with reduced quality of life and more
severe symptoms (Simren et al., Scand J Gastroenterology 2001;36:545-52).
Caution is therefore needed in the interpretation and generalization of the
reported results. These aspects should be thoroughly discussed in the
manuscript.
3) A recently published study (Cogliandro et al., Neurogastroenterol Mot 2011,
e-pub) evaluated clinical features, small bowel motility, and quality of life in
patients with chronic idiopathic intestinal pseudo-obstruction (CIIP) or severe
functional gastrointestinal disorders (SFGDI), in comparison with patients with
IBS. In contrast to the present study, mean global and most of individual scores
of severity of digestive symptoms were all significantly higher in CIIP patients and
SFGDI patients than in patients with IBS. This study should be quoted in the
discussion, analyzing the reasons that led to such different results.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
'I declare that I have no competing interests'