Background: Managing chronic constipation is challenging as patients frequently remain dissatisfied with laxative treatments. Novel studies using transabdominal electrical interferential therapy in children have shown benefit but there are inadequate adult studies. Aim: To examine the effects of transabdominal interferential stimulation on bowel symptoms and quality of life in women with refractory constipation. Methods: In a single-blind, randomised, sham-controlled pilot study, women aged ≥18 years with refractory constipation were randomised to receive interferential stimulation (with crossing of electric currents) or a novel sham stimulation (with no crossing of currents) for 1 hour a day for 6 weeks. Primary outcome was the number of patients with ≥3 spontaneous bowel movements/week. Secondary endpoints included change in PAC-SYM (Patient Assessment of Constipation-SYMptoms), PAC-QOL (Patient Assessment of Constipation-Quality of Life) and an overall symptom severity score (measured at baseline, mid time point of stimulation, end of treatment and 3 months after cessation of treatment). Results: Interferential therapy (n = 17) met the primary outcome in 9(53%) compared with 2(12%) with sham therapy (n = 16) (P = 0.02). Interferential therapy resulted in reductions in PAC-SYM (P = 0.03) and overall symptom scores (P = 0.05). Laxative use more than halved in 66% with interferential therapy compared with 14% with sham therapy (P = 0.01). Significant improvements in symptom outcomes were maintained at 3 months. There were no treatment-related adverse effects. Conclusion: Transabdominal interferential electrical stimulation is effective in reducing constipation in adult women. Three months after therapy, response is maintained and quality of life improved. Not allowing currents to cross intra-abdominally was an effective placebo. (Australianclinicaltrials.gov.au ACTRN12614000736640).