Carmint contains total extracts of Melissa officinalis, Mentha spicata, and Coriandrum sativum, which have antispasmodic, carminative, and sedative effects. As abdominal pain/discomfort and bloating are commonly observed in patients with irritable bowel syndrome, we decided to evaluate the effectiveness of Carmint in relieving these symptoms in irritable bowel syndrome patients. We randomly assigned 32 irritable bowel syndrome patients to receive either Carmint or placebo, plus Loperamide or psyllium (based on their predominant bowel function), for 8 weeks. T-test analysis of the results showed that the severity and frequency of abdominal pain/discomfort were significantly lower in the Carmint group than the placebo group at the end of the treatment (P = 0.016 and P = 0.001, respectively), as were the severity and frequency of bloating (P = 0.02 and P = 0.002, respectively). This pilot study suggests that Carmint plus loperamide or Carmint plus psyllium (depending on the irritable bowel syndrome subtype) might be effective in these patients.