In many instances, diarrhea will improve on its own (though it's still important to avoid the dehydration diarrhea may cause). Over-the-counter medications that may help treat diarrhea include Imodium, Pepto-Bismol, and Kaopectate; however, if your diarrhea is caused by a bacterial infection or a parasite, these drugs will only prolong the problem. Antibiotics may be necessary in some cases. After your diarrhea has stopped, you can start returning to a normal diet by eating soft, bland foods.
In most cases, diarrhea does not need to be stopped with anything but time -- usually a day or two. But it's important to replace lost fluid during this time to prevent dehydration (see Diarrhea Treatment). In some cases, medicines may also be helpful in treating diarrhea.
Medicines that stop diarrhea may be a helpful form of treatment for some people; however, people whose diarrhea is caused by a bacterial infection or a parasite should not use such drugs. Stopping the diarrhea in these cases traps the organism in the intestines, prolonging the problem. Instead, doctors usually prescribe antibiotics as the main diarrhea treatment in these cases.
There are several medicines available without a prescription that may help with diarrhea. These diarrhea medicines include loperamide (Imodium®) and bismuth subsalicylate (Pepto-Bismol® and Kaopectate®). Loperamide slows down the speed of fluids moving through your intestines. Bismuth subsalicylate works by balancing the way fluid moves through your intestines.
Stop taking these medicines if symptoms get worse or if your diarrhea lasts more than two days. Serious complications (such as toxic megacolon, sepsis, and disseminated intravascular coagulation) have been reported as a result of using these medications to treat some types of diarrhea.
You should call your healthcare provider before starting any medication for diarrhea, including over-the-counter medicine.