Irritable bowel syndrome symptom severity improves equally with probiotic and placebo

Figure 1 Study outline. Volunteers were selected for screening visits by a prescreen for compliance over the phone. Eligible volunteers entered an 8-wk run-in period without any investigational product (IP) consumption and were thereafter randomized to receive low- or high-dose active IP or a placebo IP for 12 wk. The intervention period was followed by a 4-wk washout period without any IP consumption. Preceding each time point (weeks 0, 4, 12, and 16), volunteers recorded their stool consistency during each defecation event for 7 d. At each time point, questionnaires [Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS); IBS-related Quality of Life (IBS-QoL); Hospital Anxiety and Depression Score (HADS)] were filled out. All volunteers were contacted by phone prior to each sampling time point to inquire about adverse events (AEs) and to remind of the sampling procedures.