The Aim of This Study is to Gain Insight Into the Occurrence of Irritable Bowel Symptoms During Ovarian Stimulation in Individuals With PCOS and in Women Who Wish to Freeze Their Eggs. This Study Uses Questionnaires.

This exploratory study investigates the impact of fertility treatments on symptoms of irritable bowel syndrome (IBS) in women. Specifically, the study focuses on two groups: * Women with polycystic ovary syndrome (PCOS) who are starting their first IVF cycle. * Women who choose social freezing (freezing eggs for social reasons). Background and Rationale PCOS is an endocrine disorder with hormonal and metabolic abnormalities associated with reduced fertility. There are four PCOS phenotypes, of which phenotypes A and B are the "classic" forms. Social freezing is becoming increasingly popular as an option for women without a partner who want to preserve their fertility. IBS is a common gastrointestinal disorder involving motility disorders and a disturbed gut-brain axis. There is an increased risk of anxiety and depression in IBS patients. Women with PCOS have a twofold increased risk of developing IBS. However, little is known about the effect of hormonal fertility treatments on IBS symptoms. Objectives * Primary objective: To investigate whether fertility treatments influence the prevalence and severity of IBS symptoms. * Secondary objective: To investigate this change in IBS prevalence and severity in relation to: * Changes in anxiety and depression scores. * Changes in general gastrointestinal complaints. * Subgroup analyses based on: * Type of stimulation * Duration of desire to have children * Ethnicity * PCOS type * Hormonal and ultrasound response Study design The study is a prospective, interventional exploratory study in which participants complete questionnaires before and after the hormonal stimulation phase. * Start date : March 1, 2026 * End date of data collection: February 2027 * Participation locations: Fertility Clinic UZ Brussels * Target sample size: 120 women (60 per group) Data collected Before treatment: * Demographics (height, weight, ethnicity) * Medical history related to fertility * PCOS phenotype (in study arm) After treatment: *