Study to Determine the Best Way to Measure How Quickly the Drug Can Give Relief From Sudden Diarrhea

Inclusion Criteria: * Diagnosis of acute diarrhea with gas-related abdominal discomfort, meeting specific criteria * Willing to follow the protocol requirements and comply with protocol restrictions, including use of contraception * Able to understand the informed consent process and sign the form * Cooperative, reliable and willing to comply with the protocol requirements and schedule, and able to record efficacy and safety assessments. Exclusion Criteria: * Female subjects who are pregnant, lactating or experiencing perimenstrual abdominal or pelvic discomfort * Illness requires hospitalization, IV fluids or antibiotics * Has taken antibiotics in the past 7 days or a symptomatic antidiarrheal compound in the past 12 hours or any analgesic in the past 6 hours * History of significant underlying enteric, pulmonary, hepatic, cardiac, renal disease, seizure disorder, IBD, cancer, uncontrolled diabetes, or any other unstable medical condition * History of hypersensitivity to loperamide or simethicone * Has previously participated in this study or received an investigational drug within the 30 day period before screening