You're at a lunch meeting or on a date, and suddenly—you've really, really got to go. Diarrhea can be caused by a number of triggers, from spoiled food to certain medications. Luckily, relief may only be a pharmacy trip away. Antidiarrheals may reduce the number of watery bowel movements you experience, and clear liquid beverages will help replace the fluids you've lost. Also see upset stomach remedies.