This white paper is the second publication in the Understanding Recurrent and Chronic Cystitis series by the European Cystitis Observatory (ECO). It explores the role of dietary patterns, hydration habits, food intolerances, and bowel regularity in different types of cystitis and in the day-to-day symptom burden. The report is based on the Dimann dataset, a large collection of anonymised, patient-reported questionnaires originally gathered during the Dimann product-assignment process. While the dataset was not initially designed to answer specific research questions, it provides a unique opportunity for exploratory, real-world insights into behavioural and nutritional factors related to cystitis. The analysed sample includes 34,000+ questionnaires collected between January 2022 and May 2025, across four European countries (Italy, Spain, France, Germany). The dataset is predominantly Italian (Italy: 32,457 observations; 94.7%), and reflects a largely female sample (98.1% women), with a mean age of 40 years. Key findings suggest distinct mechanisms across outcomes: nutritional variables (diet patterns and intolerances) appear more strongly associated with the type of cystitis reported, while hydration habits and bowel regularity are more connected to the perceived symptom burden. The paper highlights that “reactive” hydration (drinking more only during acute episodes) may be an indicator of more intense episodes, and that reduced bowel regularity is associated with higher likelihood of painful/systemic symptoms. What this publication includes A structured overview of why diet and hydration matter in cystitis management, with supporting evidence The rationale, structure, and analytical potential of the Dimann dataset (including country coverage and sample composition) A descriptive and analytical exploration of dietary regimens, hydration patterns, food intolerances, and bowel regularity Results linking behavioural/nutritional variables to both cystitis type and patient-reported symptoms Methodological note, limitations, and practical highlights to support further research and more integrated, patient-centred approaches Disclosures & provenance Issued by the European Cystitis Observatory (ECO). Conclusions and interpretations are those of ECO.Prepared by Nami Consulting (Maria Ascolese, Erica Ravarelli) using a dataset provided by Dimann.Contributors: Alessio Fabbricatore (Biologist & Functional Nutritionist) – literature review support.Funding: Yellow People Lab (owner of the Dimann brand).Clinical review: Dr. Oreste Risi, MD (Urologist).