1. Ethical guidelines

The Journal adheres to the ethical guidelines for research and publication described in “Uniform Requirements for Manuscripts Submitted to Biomedical Journals: Writing and Editing for Biomedical Publication” (http://www.icmje.org; International Committee of Medical Journal Editors [ICMJE]), “Good Publication Practice Guidelines for Medical Journals” (https://www.kamje.or.kr/board/view?b_name=bo_publication&bo_id=13&per_page=; the Korean Association of Medical Journal Editors [KAMJE]), and “Guidelines on Good Publication” (http://publicationethics.org/resources/guidelines; Committee on Publication Ethics [COPE]).

2. Authorship

All authors must have made a significant intellectual contribution to the manuscript, in accordance with the criteria formulated by the ICMJE. Each author should have participated sufficiently in the work to take public responsibility for the content. Authorship credits should be based only on substantial contributions to conception and design, the analysis and interpretation of data, drafting the article, revising it critically for important intellectual content, or giving final approval of the version to be published. General supervision of the research group is not sufficient for authorship. All authors must state they have approved the final draft submitted. Authors submitting to Gut and Liver will be required to indicate the contribution(s), each has made to the manuscript. Brief communications, imaging and issues, and letters to the editor may have one first author and one corresponding author. All authors are required to provide his/her “Open Researcher and Contributor iD “(ORCID), when submitting a manuscript to Gut and Liver. During the submission process, authors will have the option to either create an ORCID iD or associate an existing ORCID iD to their account. To learn more about ORCID, please visit https://orcid.org/about.
Any changes to the list of authors after submission, such as a change in the order of the authors or the deletion or addition of authors, need to be approved, following the submission of a letter requesting the change signed by all listed authors and from the author(s) to be removed or added. Such changes should be explained in writing to the editor in a letter or email from the corresponding author and submitted prior to the final decision of review.
It is the responsibility of the authors to determine the order of authorship. Gut and Liver will not and cannot take any part in adjudicating authorship disputes.

3. Conflicts of interest

The authors must acknowledge any conflict of interest that relates to the submission. Conflicts of interest may involve any of the following issues: acting as a guarantor of the article; certain types of author contributions; providing financial support; having potentially competing interests.

4. Copyright

In view of copyright laws, accepted papers must be accompanied by completed assignment forms. These forms are available on the website http://www.gutnliver.org/thesis/File/Copyright_form.pdf. Papers will only be published once the copyright is completed.
The corresponding author is required to download and consolidate the Copyright Assignment & Warranties Form, and have all authors sign it. The form includes a statement indicating the full transfer of copyright to Gut and Liver.
The copyright to all published materials is owned by the eight affiliated societies. (https://www.gutnliver.org/content/about/jointly_owned_operated.html)

5. Informed consent

Human studies must conform to ethical standards and be approved by the appropriate Institutional Review Board (IRB). A statement concerning IRB approval and consent procedures must appear at the beginning of the Methods section of the paper. Any systematic effort to gather data from patients or volunteers must be approved by an IRB or conform to appropriate local or national regulations. Authors may be questioned about the details of their consent forms or about the consent process. On occasion, the Editor-in-Chief may request a copy of the approved IRB application from the author.

6. Statement of human and animal rights

Clinical research studies must state that all work was carried out in compliance with the Ethical Principles for Medical Research Involving Human Subjects outlined in the Helsinki Declaration in 1975 (revised in 2000). Clinical studies that do not meet the Helsinki Declaration guidelines will not be considered for publication. Human subjects must not be identifiable.
A patient’s name, initials, hospital number, date of birth, or other protected healthcare information must never be disclosed.
Animal research studies must state that all work was carried out in compliance with the National or Institutional Guide for the Care and Use of Laboratory Animals; the ethical treatment of all experimental animals must be ensured.

7. Originality and duplicate publication

All submitted manuscripts should be original; they should not be under consideration for publication by any other scientific journal at the same time. No part of the accepted manuscript should be duplicated in another scientific journal without permission from the Editorial Board. If duplicate publications related to papers submitted to Gut and Liver are detected, the papers in question may be rejected, based on the decision of the journal’s Research Ethics Committee.

8. Obligation to register a clinical trial

Clinical trials (defined as “any research project that prospectively assigns human subjects to intervention and comparison groups to study the cause-and-effect relationship between a medical intervention and a health outcome”) should be registered in a primary registry prior to publication. Gut and Liver accepts registration in any of the primary registries that participate in the WHO International Clinical Trials Portal (https://www.who.int/); http://www.actr.org.au/; http://www.clinicaltrials.gov/; http://www.isrctn.org/; https://www.umin.ac.jp/ctr/index/htm/; http://www.trialregister.nl/). The clinical trial registration number must be published at the end of the abstract.
The reporting of randomized controlled trials should follow the guidelines laid out in the CONSORT Statement (http://www.consortstatement.org).

Manuscripts may be sent directly to the Editorial Office or submitted online via the journal’s website (http://gutnliver.org). Gut and Liver uses an online submission and review system.
Please register with our online submission system or contact the Editorial Office if you are unable to submit online.

All papers submitted to Gut and Liver are reviewed by the editorial team before being sent out for an external blind peer review; this is done to check for papers that have low priority, insufficient originality, scientific flaws, or the absence of a message of importance to the readers of the Journal. A decision on these papers is usually made within two or three weeks.
The remaining articles are usually sent to two reviewers. The average number of days between the date the manuscript was received and the first decision is 17. It would be very helpful if you could suggest a selection of reviewers and include their contact details. We may not always use the reviewers you recommend, but suggesting reviewers will make our reviewer database much richer; in the end, everyone will benefit. We reserve the right to return manuscripts in which no reviewers are suggested.
The final responsibility for the decision to accept or reject a paper lies with the editors. In many cases, papers may be rejected despite favorable reviews because of editorial policy or a lack of space. The editor retains the right to determine publication priorities, the style of the paper, and to request, if necessary, that the material submitted be shortened for publication.

The cover letter should inform the editor that neither the submitted material nor portions thereof have been published previously or are under consideration for publication elsewhere.
When more than one related manuscript has been published or is under consideration for publication by this or other Journals, authors are required to declare this in their letter and to enclose copies of the relevant publications for editorial review. Failure to do so may lead to an automatic rejection of the submitted manuscript. The corresponding author should certify that all listed authors participated meaningfully in the study and that they have seen and approved the final manuscript. The cover letter must briefly explain each author’s individual contributions.

The manuscript must be double-spaced with 3 cm margins on A4 sized paper. Please number the pages consecutively, beginning from the title page.

1. Title page

The title, together with each author’s full name and institu-tional affiliation(s) should be typed on the title page in the Journal’s house style. A running title should be added if the title exceeds 12 words. The corresponding author’s name, full address, telephone and facsimile numbers, and e-mail address should also be included, if necessary, in a footnote.
Provide a short descriptive statement regarding the contributions of each co-author (e.g., study concept and design; data acquisition; data analysis and interpretation; drafting of the manuscript; critical revision of the manuscript for important intellectual content; statistical analysis; obtained funding; administrative, technical, or material support; study supervision).

2. Abstract

Authors of original scientific papers must supply a structured abstract of no more than 250 words, incorporating the following headings: Background/Aims, Methods, Results, and Conclusions. Nonstandard abbreviations, references, or footnotes should not be used. A maximum of five key words should appear below the abstract, using MeSH terms.

3. Main text

All clinical research papers that involve human or animal subjects must be accompanied by evidence of an Institutional Review Board or Ethics Committee Review. The maximum word count is 3,500 words. References should be critical and relevant to the manuscript, figure legends, tables, and illustrations. All original manuscripts must include the following:

• Introduction — Summarize the rationale for the study and outline pertinent background material. The introduction should not contain either results or conclusions.
• Materials and Methods — Describe your methods in sufficient detail to enable another investigator to repeat the work. Include the name and location (city, state, country) of any manufacturer mentioned in the text. Outline any statistical methods used. Either describe the ethical guidelines used for human or animal study or provide evidence of the approval granted by an institutional human research review committee or animal welfare committee. Describe in detail any hazardous procedures or chemicals used, and the precautions observed.
• Results — Present the results in a logical sequence in the text. Avoid presenting the same data in different forms, for example through tables or illustrations. Do not include aspects of the discussion in the results section.
• Discussion — The discussion should demonstrate how any results obtained relate to the original hypotheses advanced in the introduction. This explanation may include an evaluation of the methodology and of the relationship of new information to the existing corpus of knowledge in that field. Data presented in the results section should not be reiterated here.

Brief communications are short articles describing clinical or experimental findings of significant importance or advancement. A brief communication should include an unstructured abstract of no more than 200 words. The main text should be limited to 1,500 words, with no more than 15 references. The total number of tables and figures should not exceed two.

This section presents unusual, classic, challenging, or informative images in the field of gastroenterology. Submissions will be reviewed by the Imaging and Issues Coordinating Editors. The format should include a title page, case description, discussion, references, and images. The case description should be no longer than one page, and should include the following: a brief history, findings during the physical exam, laboratory results, the clinical course, and the outcome. The case images and all of the labels within the images must be described. The discussion and references should be no longer than one page. The discussion should include important features of the images, the differential diagnosis, and the clinical significance. No more than five references should be included. References must include definitive studies and pertinent reviews. No more than two high quality figures will be accepted.

The Journal welcomes readers’ comments on articles published recently in the Journal or on topics of interest.

Substantive reviews of systematic and clinical topics in gastroenterology and liver disease will be considered for publication. Both types of manuscript will be peer reviewed prior to consideration for publication. An abstract must be included.

Perspectives are mini reviews focusing on recent outstanding interests in the field. The length of the text should be up to 2000 words with a maximum of 30 references. The total number of tables and figures should not exceed four.

Editorials express opinions on current topics of interest or provide comments on papers published elsewhere in the same issue. Editorials are usually solicited by the Editor. Tables and/or figures may be included. Editorials should have fewer than five authors and should not exceed 1,000 words. No subdivisions (such as an Introduction, Materials and Methods, Results, or Discussion) are required. A maximum of 10 references may be included.

4. Conflicts of interest

Any potential conflict of interest relevant to the article must be described.

5. Acknowledgements

A brief acknowledgement of persons who made a genuine contribution may be included. Authors are responsible for obtaining written permission to use any copyrighted text and/or illustration. All funding related to the work should be specifically acknowledged.

6. References

Please number references serially in the text in order of citation, with the numbers printed in superscript. List all authors if there are fewer than seven. List the first three authors followed by “et al.” if there are seven or more authors. Journal titles should be abbreviated in the style of Index Medicus. For more on references, please refer to the National Library of Medicine (NLM) Style Guide for Authors, Editors, and Publishers (http://www.nlm.nih.gov/citingmedicine)

• • References to an article with six or fewer authors: Meltzer SJ, Abnen DJ, Battifour A, Yokokota J, Cline MJ. Protooncogene abnormalities in colon cancer and adenomatous polyps. Gastroenterology 1987;92:1174-1180.
• • References to an article with more than six authors: Shim SG, Rhee JC, Rhee PL, et al. Mechanism of motilin action on smooth muscle of the human stomach. Korean J Gastroenterol 2002;39:4-12.
• • Reference to a book: Day RA. How to write and publish a scientific paper. 3rd ed. Phoenix: Oryx, 1988.
• • Reference to a chapter in a book: Costa M, Furness JB, Llewellyn-Smith IF. Histo-chemistry of the enteric nervous system. In: Johnson LR, ed. Physiology of the gastrointestinal tract. Volume 1. 2nd ed. New York: Raven, 1987:1-40.
• • Website: World Health Organization (WHO). WHO statistical information system [Internet]. Geneva: WHO; c2010 [cited 2012 Jan 5]. Available from: http://www.who.int/whosis/en/menu.cfm.

7. Tables

Each table must be simple and typed on a separate page with its heading above it. Explanatory material should be placed in footnotes below the table, and should not be included in the heading. All non-standard abbreviations should be explained in the footnotes (indicated by *, †, ‡, §, Ⅱ, ¶, #). Statistical measures such as SD or SEM should be identified. Vertical and horizontal rules between entries should be omitted. Each table should be referred to consecutively and numbered in order of citation. Tables should be double-spaced, including headings. Larger sheets of paper must not be used. Tables should be numbered consecutively in Arabic numerals beginning with 1.

8. Figure legends

Figure legends should be double-spaced on a separate sheet. Symbols, arrows, and letters should be used to indicate parts of illustrations. Each figure should be referred to in the text consecutively and should be numbered in order of citation.

9. Figures

We encourage authors to use colored figures if they will enhance the presentation of the data. Only high-resolution figure files (Minimum 300 dpi) should be submitted, preferably in JPEG or EPS format. Adherence to these requirements from the outset will prevent the Production Editor from contacting the author at a later stage for better quality figures.

10. Terminology

When using medical terminology, please adhere to the standard usage found in the guide to terminology recently published by the Korean Medical Association (http://term.kma.org/).

11. Abbreviations

Laboratory measurements should be in SI units (International System of Units). The metric system is preferred when expressing length, area, mass, and volume.

12. Units of measurement

Laboratory measurements should be used in SI units (International System of Units). The metric system is preferred for the expression of length, area, mass, and volume.

1. Original articles, review articles

US\$1000 per accepted article.
*Invited articles are exempt from article processing charges.

2. Brief communications, Perspectives, and letters

US\$250 per 4 printed pages or fewer; US\$50 per additional page.

3. Color charges

US\$100 for each illustration containing color.

4. Author reprints

US\$50 for 100 copies. VAT will be added.