OBJECTIVES: To assess the impact of treatment response on quality of life (QOL) and work productivity for patients with irritable bowel syndrome with constipation (IBS-C). METHODS: Irritable Bowel Syndrome - QOL (IBS-QOL) score, EQ-5D index score, work productivity, and IBS symptom relief were collected in two phase III randomized placebo-controlled clinical trials of linaclotide, an investigational treatment for IBS-C.  Treatment response for IBS-C was defined as (1) a ≥ 14-point increase at Week 12 from baseline on the overall IBS-QOL score or (2) moderately or significantly relieved on a seven-point Likert scale on global symptom relief for ≥ 2 out of 3 months.  Hours of work missed due to IBS-C were collected using the Work Productivity and Activity Impairment (WPAI) Questionnaire.  Data from the intent-to-treat populations were pooled for linaclotide and placebo across two trials.  EQ-5D index score and work productivity were evaluated among responders and non-responders. RESULTS: Patients were analyzed with available EQ-5D and IBS-QOL data (n=1,487) and available EQ-5D and IBS symptom relief data (n=1,558), with response rates of 46% and 14% respectively.  Patients were analyzed with available WPAI and IBS-QOL data (n=1,056) and WPAI and IBS symptom relief data (n=1,103), with response rates of 47% and 15%, respectively.  Responders had statistically significantly higher EQ-5D scores at Week 12 than non-responders, for both definitions (IBS-QOL: 0.85 vs. 0.81, IBS symptom relief: 0.91 vs. 0.81, both P<0.05).  Responders were statistically significantly less likely to miss ≥1 hour of work during 12 weeks for IBS-C (IBS-QOL: 16.0% vs. 21.7%, IBS symptom relief: 9.6% vs. 20.8%, both P<0.05). CONCLUSIONS: Improvements in disease-specific measures correlate with improvements in health utilities and reduced work absenteeism among patients with IBS-C.