This study was designed to evaluate the effect of temporary sacral nerve stimulation in patients with diarrhea-predominant irritable bowel syndrome. Symptoms of diarrhea-predominant irritable bowel syndrome and disease-specific quality of life was evaluated in six patients before and during percutaneous sacral nerve evaluation test. Primary end points were differences between total irritable bowel syndrome symptom score and total quality of life score before and during stimulation. Secondary end points were differences between the variable domains. Percutaneous sacral nerve evaluation test was performed in five women and one man (median age, 33 (range, 26-54) years). The irritable bowel syndrome symptom score decreased from 48.9 to 28.3 (P = 0.004). Pain, bloating, and diarrhea were significantly reduced from 7.9, 13.5, and 17.3 to 4.4, 7.2, and 10.6, respectively (P = 0.02, P = 0.01, P = 0.03). The irritable bowel syndrome quality of life score decreased from 99.3 to 59.6 (P = 0.009). Daily activities, emotional distress, eating habits, and fatigue were significantly reduced from 26.9, 22.2, 15.2, and 23.2 to 16.9, 13.3, 8, and 14.4, respectively (P = 0.02, P = 0.02, P = 0.02, P = 0.007). Two weeks after cessation of stimulation, the patients had symptoms as before stimulation. Temporary sacral nerve stimulation provides a significant reduction in diarrhea-predominant irritable bowel symptoms and improves quality of life. Further studies with permanent implantation and double-blind crossover ON-and-OFF-stimulation to evaluate the impact of placebo effect are needed.