Fig. 3

Modified daily Gastrointestinal Symptom Rating Scale scores differed by day of menstrual cycle (P < 0.05). 1 = no discomfort at all, 7 = very severe discomfort for abdominal pain (abdominal pain, hunger pains, and nausea), diarrhea (diarrhea, loose stools, and urgent need for defecation), constipation (constipation, hard stools, and feeling of incomplete evacuation), indigestion (rumbling, bloating, burping, and gas), and reflux (heartburn and acid regurgitation) syndromes. Panel A depicts all scores together on the scale used in the questionnaire; panels B-F depict individual syndrome scores with results from post hoc tests. Data represent the means±SEM. Day 1 represents the first day of menstruation. The significant effect of day was determined by using generalized linear mixed models. Post hoc Dunnett’s tests for multiple comparisons identified days of interest (*P < 0.05 vs Day 1)