Further validation of the visual analogue scale for irritable bowel syndrome after use in clinical practice.

The Visual Analogue Scale for Irritable Bowel Syndrome (VAS-IBS), a self-rating questionnaire, was designed to measure symptoms and the effect of treatment in patients suffering from irritable bowel syndrome. The aim of this descriptive correlational study was to conduct further psychometric validation after the VAS-IBS had been used in clinical practice, translate it into English, and compare the results with controls. Forty-nine patients with irritable bowel syndrome (median age = 38 years old [range, 18-69 years]) were compared with 90 healthy persons (median age = 44 years old [range, 21-77 years]) who served as controls. The patients with irritable bowel syndrome completed 3 questionnaires: the VAS-IBS, the Gastrointestinal Symptom Rating Scale, and the Perception of Change of Symptoms. Controls completed only the VAS-IBS. Results showed that the VAS-IBS is a valid questionnaire that measures the degree of change of symptoms and discriminates between patients who have irritable bowel syndrome from those who do not. It is important to compare the VAS-IBS among different cultural populations so we suggest that the English version of the VAS-IBS should now be used in English-speaking countries and be further tested for validity and reliability with English-speaking patients.