BackgroundMedical treatments for irritable bowel syndrome (IBS) are often disappointing. A colonic irrigation system, the Ashong colonic irrigation apparatus (ACIA), was designed as a patient-administered device for defecation disorders. This pilot study evaluated the efficacy and safety of ACIA for IBS.MethodsEighteen patients, 12 with constipation-dominant IBS (IBS-C) and 6 with diarrhea-dominant IBS (IBS-D) group, were studied. Patients were randomized into treatments of 1–4 weeks. Colonic irrigation was performed twice daily for 6 consecutive days per week. To determine the response to treatment, bowel movement frequency, stool consistency, abdominal pain, patient satisfaction with bowel movements, and distress/discomfort due to symptoms were assessed.ResultsThe scores of abdominal pain (p < 0.001), satisfaction (p < 0.001), and distress/discomfort (p < 0.001) improved significantly. The frequency of bowel movements in the IBS-C group increased from 1.68 to 3.78 times per week (p < 0.001). The occurrence of Bristol Stool Scale type 1 and 2 stool passage decreased from 45 to 13 % (p = 0.009) in the IBS-C group and type 6 and 7 stools decreased from 62 to 28 % (p = 0.005) in the IBS-D group. Only mild adverse events occurred, and all patients completed treatment.ConclusionsColonic irrigation with ACIA is safe and can improve abdominal pain, constipation, and diarrhea associated with IBS. Patients were more satisfied with their bowel movements and found their symptoms were less disturbing. Larger studies on long-term efficacy and quality of life and on placebo effects are needed.