Antidiarrheal Medicines

What are antidiarrheal medicines?

Antidiarrheal medicines are used to decrease the number of diarrheal stools or to stop diarrhea. Diarrhea means frequent loose bowel movements (stools).

Most people have diarrhea once in a while. It may be caused by stomach flu or by eating or drinking contaminated food or water. Diarrhea can be very serious in older adults. It can cause dehydration (a loss of too much fluid from the body). Antidiarrheal medicines may be used to treat diarrhea for a short time (1 to 2 days).

How do these medicines work?

There are 3 main types of antidiarrheal medicines:

• stool thickeners
• antispasmodic medicines
• bulking agents.

Stool thickeners (such as Kaopectate) absorb bacteria and toxins in the intestines. They also thicken the stool with clay or fruit pectin. Antispasmodic medicines (such as Imodium) slow down the passage of food and stool through the intestines. This allows time for more water to be absorbed from the stool into the intestines. It results in fewer and firmer stools. Many antidiarrheal medicines contain both a stool thickener and an antispasmodic medicine. Bulking agents are another way to thicken the stool. They contain fibers made from plant seeds. The fibers form a thickening gel inside the intestines. A well-known bulking agent is Metamucil, which contains psyllium fiber.

When are they used?

You should use these medicines only when you really have to. For example, if you are traveling and have diarrhea, you may need medicine for the times when you cannot get to a bathroom.

Use stool thickeners or antispasmodic medicines for a short time only. They can cause severe constipation, and they can make the illness more severe. If you have a bacterial infection, diarrhea is your body's way of getting rid of the bad bacteria. If your diarrhea lasts more than 2 days, ask your healthcare provider if it is OK to use antidiarrheal medicines and if so, for how long. Your provider may want you to come to the office to be checked.

What should I watch out for while taking these medicines?

Carefully read the label on the medicine package for instructions, warnings, and ingredients. Do not use these products for more than 2 days without getting advice from your provider.

Call your provider if:

• You have blood in your stools.
• You have a fever of 101.5°F (38.6°C) or higher with diarrhea.
• You have vomiting with your diarrhea and are unable to keep any liquids down for 24 hours.
• Your symptoms do not get better within 2 or 3 days, or they get worse.