Review for 10.1186/1471-230X-9-27 (2009)

Reviewer's report
Title:Development of functional gastrointestinal disorders after Giardia lamblia
infection
Version: 1Date:24 November 2008
Reviewer: Peter Whorwell
Reviewer's report:
This study describes the apparent development of irritable bowel syndrome (IBS)
in a cohort of patients who had previously suffered from infection with giardia
lamblia.
General Comment
The findings described are of interest but the report does lack detail which many
readers would feel should be included.
Specific Comments
1. Introduction: The first report of post-infective IBS was actually published more
than twenty years ago by Chaudhary & Truelove in 1962.
2. Introduction: Post-infective IBS, and for that matter functional dyspepsia, have
in fact been reported after other types of infection for example viruses and even
protozoan parasites and this has not been mentioned. These observations
obviously suggest that any form of gastrointestinal infection may result in
post-infectious IBS and that problems following giardiasis might be anticipated.
3. Methods: We are told functional dyspepsia was sought after but not given any
detail of how this was identified.
4. Methods: We are told some patients were re-biopsied one year later, but not
informed whether the whole group was followed up. It would be very important to
assess whether symptoms diminished or resolved over time and as they have
recorded symptom scores should be possible to ascertain. This point is important
because people with non-specific diarrhoea can develop persisting symptoms for
a surprisingly long time after the initial event.
5. Methods: it would have been nice to have a control group to see how many
people spontaneously developed symptoms over a similar period of observation.
6. Results: We are told most people denied previous abdominal illness before
their infection. It would be important to know how this was established especially
as it seems that many may not have consulted a doctor. Many people deny
abdominal symptoms unless specifically asked about problems such as
difficulties with bowel function or bloating which they may not have consulted
about. This issue does not necessarily mean that the findings reported here are
irrelevant as gastrointestinal infections also make established IBS worse.
7. Results: They report that many patients claimed to be intolerant of milk.
Lactase deficiency can follow gastrointestinal infections – did they undertake any
lactose tolerance testing.
8. Discussion: There is a lot of interest in the role of low grade inflammation in
IBS especially in relation to the post-infective variety of this condition.
9. Discussion: Antibiotics can lead to IBS and there is a literature on this which
probably ought to be quoted. Presumably these patients were treated with
antibiotics and this issue needs discussing.
10. Discussion: The authors dismiss female gender as a risk factor although I
think (but I am not certain) that female gender has been reported as a risk factor.
11. Discussion: I have previously referred to a range of organisms being
responsible for post-infective IBS, if the authors decide not to mention it in the
Introduction it should certainly be covered in the discussion.
12. Discussion: The role of stress is dealt with very superficially. It would be
worth discussing this in more detail in the light of previous data suggesting
psychological factors predict the development of IBS following infection.
Other required comments:
Major Compulsory Revisions (which the author must respond to before a
decision on publication can be reached)
An article whose findings are important to those with closely related research
interests
English: Acceptable
I do not feel adequately qualified to assess the necessity for statistics.
I declare that I have no competing interests
Quality of written English: Acceptable
Declaration of competing interests:
I declare that I have no competing interests