Introduction

It is estimated that approximately one in 500 people in the UK currently have a stoma.1 A stoma is a surgical opening in the abdomen formed to divert the tract through which feces or urine is excreted.2 Ileostomies and colostomies are the most common forms of stoma and are created to enable fecal contents to be discharged into an external pouch from the ileum or colon, respectively.2 Jejunostomies are a less common form of intestinal stoma, for removal of fecal contents from the jejunum.3 Urostomies are a type of stoma created for urine excretion.2 Collectively, these different types of stoma are often referred to as ostomies and people with a stoma called ostomates. Stomas for fecal excretion are created when there is damage or disease to the intestine and part of the small and/or large intestine needs to be rested for a long period or removed.4 Commonly, this occurs in conditions such as colorectal cancer, Crohn's disease and ulcerative colitis.5

The issues and nutrition-related complications associated with stomas vary between the types of stoma. The risk of nutrition-related complications and the need for dietary intervention is greater in people with a stoma of the gastrointestinal (GI) tract than those with urostomy.6 From this point forward, the term stoma or ostomy will be used to refer only to ileostomy, colostomy and jejunostomy. Urostomies will not be considered further within this review.

A colostomy usually passes soft, formed stool approximately once daily, depending on diet and physical activity,6 whereas normal output for an ileostomy is approximately 600-800 ml/day of loose feces of porridge-like consistency.7 People with an ileostomy, and even more so with jejunostomy, are at greater risk of nutritional deficiencies than people with a colostomy due to removal of the colon and varying amounts of the ileum.8,9 The colon reabsorbs fluids and electrolytes, therefore, people with an ileostomy or jejunostomy have greater losses of these in their feces and looser output.10,11 Definition of high-output stoma varies and is usually considered as output greater than between 1L and 2L/day.8,10,11 Mismanagement of high-output stomas can lead to dehydration, acute kidney injury and malnutrition.10,12 The shorter the length of GI tract left available for digestion, the greater the risk of malabsorption of nutrients, and therefore malnutrition.13 Dietary advice involving high energy/protein diet and oral nutritional supplement drinks may be required to prevent or resolve malnutrition.10,14 People with less than 200 cm of small intestine remaining for digestion and absorption of nutrients may require artificial feeding (enteral or parenteral nutrition) to prevent malnutrition.14

Dietary management is recommended for the following complications associated with having a stoma: high output, loose output, constipation, blockage, wind and odour.6 High and/or loose output and blockage are common complications in people with an ileostomy or jejunostomy.15,16 Constipation and odour are more common complications of a colostomy.16,17 Aspects of dietary management include: fibre restriction to prevent blockage and high output;6,8,12 oral rehydration solutions and/or fluid restriction for high output;8,12 added salt for people with high output ileostomy;12 white, starchy carbohydrates and gelatine containing sweets to thicken output;18 increased fibre and fluid for constipation;6,19 and avoidance of onions, beans and carbonated drinks to reduce wind.6 Acceptability of, and adherence to, dietary interventions for stoma management is important in improving clinical and patient reported outcomes. Contradictory messages for healthy eating and some aspects of stoma management may affect adherence.20 Additionally, rehydration solutions may not be palatable to many.21

As well as affecting nutritional status, complications of having a stoma may also include detrimental effects on quality of life,22 and, for severe complications such as persistent high-output stoma and blockage, require a hospital admission.6,12 Management of complications through diet, alongside medication where diet alone is insufficient, is extremely important for patient wellbeing and to reduce burden to health services. However, despite the common use of dietary management strategies mentioned above, there is a distinct lack of current and high-quality evidence on which to base these recommendations, and much of the evidence to date appears to be from expert opinion. In practice, dietary advice for stoma management may be provided by multiple health professionals including dietitian, stoma nurse, other nurses, doctor or surgeon,6,23 or by associations offering support to people with a stoma, for example the Ileostomy and Internal Pouch Support Group.24 However, it has been reported that stoma patients commonly feel that the dietary advice they receive is insufficient, lacking in quality, inconsistent and can be conflicting.18,23,25,26 An example of variation in suggested dietary management after stoma surgery can be found within the nursing literature; one article suggests that all fruit except bananas should be avoided for a short period following ileostomy formation, and then gradually reintroduced,6 whereas another suggests that soft fruit without skins are unlikely to pose a problem.18 Discrepancies between opinion articles likely represent differences in practice within and between healthcare professions. Further work to establish the effectiveness of dietary strategies for specific types of stoma and symptoms, potentially at different time frames following surgery, is needed to inform clinical practice.

Preliminary searches of the literature suggest that insufficient evidence is available from dietary intervention studies of people with a stoma for a systematic review and meta-analysis of effectiveness to be carried out. A scoping review is proposed to identify and map the current extent and types of research and peer-reviewed expert opinion relating to the oral dietary management of ileostomies. The results of this review will be used to highlight areas in need of further research, and to inform future studies by identifying potential dietary strategies and outcomes to be investigated.

A preliminary search for existing reviews on dietary intervention for people with a stoma was carried out using the following databases: JBI Database of Systematic Reviews and Implementation Reports, PROSPERO, Cochrane Database of Systematic Reviews (CDSR), MEDLINE and CINAHL. No existing reviews similar to the proposed scoping review were found.

Inclusion criteria

Participants

This review will consider evidence relating to people with an ileostomy. Evidence relating to people with an ileostomy due to any condition, for example, Crohn's disease, ulcerative colitis, or colorectal cancer, will be included since common dietary advice for ileostomy management is provided irrespective of underlying condition.6 In practice, dietary management of the underlying condition may need to be considered alongside dietary management of the stoma.23

This review focuses on people with an ileostomy due to the greater risk of severe complications associated with dietary mismanagement compared to those with colostomies, as well as differences required in the oral dietary management of ileostomies compared to colostomies.6,27,28 Evidence relating to jejunostomies will not be included in this review because jejunostomy surgery often results in severe malabsorption requiring restriction of oral intake and reliance on parenteral nutrition.11

There will be no restriction on age or sex in order to map and describe the full extent of the evidence related to the topic. Articles relating to babies not yet fully weaned and animal studies will be excluded.

Concept

The concept being considered in this review is oral dietary management of ileostomies. Dietary strategies may include: fibre modification, low residue, reintroduction diets, added salt, fluid modification, rehydration solutions, low fat, probiotics and/or prebiotics, foods suggested to promote thickening of stoma output e.g. low fibre, starchy carbohydrate foods or gelatine containing sweets, and avoidance of specific foods associated with increased flatulence, e.g. onions and beans, or blockage, e.g. nuts and sweetcorn.6,13,18

Oral dietary management of nutritional consequences of having an ileostomy will also be included. For example, dietary advice to prevent or reverse dehydration and/or malnutrition due to high stoma output.14 Dietary advice to prevent or reduce malnutrition may include a high energy and/or high protein diet and oral nutritional supplement drinks.14

Only evidence relating to oral dietary management will be included. Where the dietary management is artificial nutrition (enteral or parenteral nutrition), this will be excluded, as it is beyond the scope of this review. If other components of oral dietary management for people with an ileostomy, that are not listed here, are found to be reported in the literature, these will also be included because this review aims to identify all types of oral dietary management that have been suggested for the management of ileostomies.

Outcomes will be aspects of stoma management including high-output stoma, loose stoma output, wind, odor, blockage, malnutrition, and dehydration.29

Context

Dietary advice may be provided in a variety of settings including hospitals, community healthcare, or via online or printed communications. Dietary advice given to patients in hospital may be relevant to or continued when they return home.26 Therefore, the context will be left open to include hospital or community settings.

Evidence for inclusion in this review will not be restricted by country, language or date to enable the full extent of available evidence to be mapped.

Types of studies

This scoping review will consider all types of quantitative and qualitative study designs and reviews (including narrative reviews and expert opinion articles termed as reviews). Quantitative studies include experimental designs (randomized and non-randomized controlled trials and quasi-experimental studies) and observational designs (cohort studies, case-control studies, cross-sectional studies, case studies and descriptive studies). Qualitative studies may include phenomenology, grounded theory, ethnography and thematic analysis methodologies. Text and opinion-based evidence to be included will be expert opinion only. Guidelines and documents disseminated by relevant associations/societies/institutions, such as international and national ileostomy associations, will be excluded as these are not usually peer-reviewed publications or research. If peer-reviewed publications of consensus guidelines are identified, these will be included.

Methods

The review will be carried out systematically using the JBI methodology for conducting scoping reviews.30

Search strategy

The search strategy aims to find published and unpublished studies, expert opinion and review articles. A three-step search strategy will be used in line with guidance from JBI.30 An initial limited search of MEDLINE and CINAHL has been undertaken followed by analysis of the text words contained in the title and abstract, and of the index terms used to describe articles. This informed the development of a search strategy which will be tailored for each information source. A full search strategy for MEDLINE is detailed in Appendix I. This meets the criteria for a draft search strategy for at least one database, required in the PRISMA-P checklist31 and by JBI.32 The reference list of all articles selected for inclusion will be screened for additional relevant articles. Subject experts will be contacted to check for completeness in the list of articles identified by the reviewers for inclusion.

Information sources

The databases to be searched include: MEDLINE, Embase and AMED via Ovid, CINAHL via EBSCO, Web of Science, CDSR, and JBI Database of Systematic Reviews and Implementation Reports. The trial registers to be searched include: ClinicalTrials.gov, WHO ICTRP, and Cochrane Central Register of Controlled Trials. The search for unpublished studies will include: OpenGrey, EThOS, ProQuest - Nursing and Allied Health Source Dissertations, and Google Scholar. All databases will be searched from date of inception.

Study selection

Following the search, all identified citations will be collated and uploaded into EndNote X8 (Clarivate Analytics, PA, USA) and duplicates removed. Titles and abstracts will then be screened by two independent reviewers for assessment against the review inclusion/exclusion criteria. Articles and documents that may meet the inclusion criteria, and no exclusion criteria, will be retrieved in full. The full text of selected articles and documents will be assessed in detail against the inclusion/exclusion criteria by two independent reviewers. Full text articles or documents that do not meet the criteria for inclusion will be excluded and reasons for exclusion will be provided in an appendix in the final review report. The results of the search will be reported in full in the final report and presented in a PRISMA flow diagram in line with international standards.33 Any disagreements that arise between the reviewers will be resolved through discussion or with a third reviewer.

Data extraction

Data will be extracted from articles and documents into a charting form by two independent reviewers. The data charted will include specific details about the author/s, date and type of publication, country of origin, type of evidence and study design (if applicable), population, diet (including comparator if applicable), outcomes, setting, and key findings or recommendations. A draft charting form has been developed to ensure that appropriate data is extracted to enable the review questions to be answered (Appendix II). This charting form will be initially tested by two independent reviewers on three articles to check that all relevant information relating to the review questions is extracted. The charting form will continue to be adapted as required during the review process and the final version will be included in the report of the scoping review. Any disagreements that arise between the reviewers will be resolved through discussion or with a third reviewer. Authors of included articles will be contacted for clarification of information when necessary.

Data presentation

Results will be presented in a tabular summary according to: i) study design, for example, randomized controlled trial (RCT), cohort study, phenomenology; or ii) article type, for example, expert opinion. A draft results table has been developed and is included in Appendix III. This table will be adapted as required towards the end of the review process to ensure that all relevant data is presented. A diagrammatic map of the evidence will also be produced to highlight the level and quantity of evidence for each dietary intervention linked with a specific outcome. A narrative summary will synthesize the findings to provide a description of the evidence identified in relation to the review questions.

Funding

This study is supported by the NIHR Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health and Social Care.

Acknowledgments

We acknowledge Katie Barnard, subject librarian at North Bristol NHS Trust, for her advice on development of the search strategy.

A version of this review protocol was submitted for a module assessment to contribute towards the degree of Master in Clinical Research funded by the NIHR at the University of Plymouth. Thanks to Katrina Bannigan, Associate Professor in Occupational Therapy at the University of Plymouth, for her feedback.

Appendix I: Search strategy for MEDLINE (Ovid)

1. Ileostomy/

2. Ostomy/

3. ostom^*.tw.

4. stoma.tw.

5. ileostom^*.tw.

6. 1 or 2 or 3 or 4 or 5

7. Diet/

8. nutrition^*.tw.

9. diet^*.tw.

10. Diet, Fat-Restricted/

11. Dietary Fiber/

12. (fibre or fiber).tw.

13. Prebiotics/

14. Probiotics/

15. (probiotic^* or prebiotic^*).tw.

16. (food or eat^* or drink^*).tw.

17. Eating/

18. Drinking/

19. fluid^*.tw.

20. Sodium/

21. sodium.tw.

22. Salts/

23. salt.tw.

24. Rehydration Solutions/

25. ("oral rehydration therap^*" or "rehydration solution^*").tw.

26. Electrolytes/

27. electrolyte^*.tw.

28. Dietary Supplements/

29. supplement drink^*.tw.

30. oral nutrition support.tw.

31. sip feed^*.tw.

32. 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31

33. 6 and 32

34. Animals/ not Humans/

35. exp Animals, Laboratory/

36. exp Animal Experimentation/

37. Models, Animal/

38. Rodentia/

39. (rat^* or mouse or mice).ti.

40. 34 or 35 or 36 or 37 or 38 or 39

41. 33 and 40

42. 33 not 41

Appendix II: Draft charting form

Appendix III: Draft table of results

References