Symptom scores, stool data, and the transit of a standard, solid meal were measured in 28 patients with irritable bowel syndrome (IBS) during baseline conditions and after five weeks of treatment with placebo and loperamide, given as a flexible dosage regime in the form of a double-blind, cross-over trial. All patients had undergone a comprehensive series of diagnostic investigations and had failed to respond to dietary supplementation with coarse wheat bran (10–30 g daily). Loperamide treatment accelerated gastric emptying, compared with placebo (1.2±0.1 vs 1.5±0.1 hr; P<0.001) and="" delayed="" both="" small="" bowel="" (6.2±0.3="" vs="" 4.3±0.3="" hr=""><0.001) and="" whole="" gut="" transit="" (56±5="" vs="" 42±4="" hr;=""><0.01). eighteen="" patients="" said="" they="" felt="" better="" taking="" loperamide="" compared="" with="" placebo="" and,="" at="" follow="" up,="" 15="" of="" these="" patients="" remained="" satisfied="" with="" the="" effects="" of="" the="" drug.="" most="" symptoms="" improved="" significantly="" on="" placebo="" compared="" with="" the="" baseline="" period,="" but="" three="" of="" these="" [diarrhea=""><0.01), urgency=""><0.01) and="" borborygmi=""><0.05)] showed="" a="" further="" significant="" improvement="" on="" loperamide.="" improvement="" in="" diarrhea="" was="" not="" associated="" with="" any="" change="" in="" stool="" weight="" but="" was="" associated="" with="" reductions="" in="" stool="" frequency=""><0.001), passage="" of="" unformed="" stools=""><0.01), and="" incidence="" of="" urgency=""><0.001). urgency="" was="" the="" only="" symptom="" that="" was="" significantly="" more="" common="" in="" the="" success="" group,="" compared="" with="" the="" group="" who="" did="" not="" feel="" better="" on="">