JMIR Publications

ABSTRACT

Background:

Gastrointestinal (GI) cancers significantly affect nutritional intake, while clinical measures offer limited insight into how patients navigate dietary decisions in their daily lives. Social media platforms, particularly comment sections, create spaces for interactive exchange in which dietary norms are collectively tested and renegotiated. Despite growing interest in online health discourse, the interactive dynamics of comment sections within GI cancer online communities remain underexplored.

Objective:

This study aimed to characterise dietary-related online discussions among a Chinese GI cancer community on Xiaohongshu, identifying prominent topics, emotional expression patterns, and the discursive processes through which dietary norms are constructed and negotiated at the community level.

Methods:

A mixed-methods approach integrating latent Dirichlet allocation (LDA) topic modelling, sentiment analysis, and Fairclough's three-dimensional critical discourse analysis (CDA) framework. Comments were collected from posts on Xiaohongshu identified through keyword searches combining GI cancer types with diet-related terms from September to December 2025, yielding 1,865 valid comments from 370 posts for analysis.

Results:

Nine topics were identified, grouped into four thematic categories: acute-phase nutritional support interventions, basic food choices and dietary principles, dietary management of common symptoms, and special conditions and metabolic diets. Sentiment analysis revealed predominantly neutral expressions (66.6%), followed by positive (21.4%) and negative (12.0%) sentiments. CDA revealed that dietary decisions were guided by risk minimization and bodily feedback rather than nutritional optimization. Interactive negotiations shifted epistemic authority from medical-centred to community-centred models. Traditional beliefs about fawu coexisted with biomedical perspectives, reflecting ongoing discursive renegotiation of cultural dietary prohibitions. Commercial discourse permeated discussions, linking disease management to consumption practices.

Conclusions:

Dietary discourse within this online community reflects complex negotiations among medical knowledge, experiential wisdom, and traditional cultural beliefs. Effective nutritional interventions require attention to patients' risk perceptions, emotional regulation through neutral language, cultural frameworks surrounding dietary prohibitions, and the commercial information environment shaping dietary decisions. Oncology nurses should integrate authoritative recommendations with patients' experiential knowledge and develop culturally sensitive approaches to nutritional counselling. Clinical Trial: This study is a retrospective observational content analysis of publicly available user-generated content on the Xiaohongshu platform, using latent Dirichlet allocation (LDA) topic modeling and sentiment analysis methods. The research does not involve any clinical intervention, human subject recruitment, experimental manipulation, or prospective clinical trial. As it is not a clinical trial or interventional study, trial registration is not required.