Ginger, an herb sold as an over-the counter supplement, has a long history of use to treat stomach ailments in Chinese herbal medicine. Ginger is still used as an alternative medicine to treat nausea and vomiting; ginger ale, although it no longer contains much, if any, real ginger, was originally used for this reason to quiet stomach upset. However, if taken in large quantities, ginger can cause other stomach problems such as diarrhea.
Ginger may decrease stomach problems such as nausea and vomiting by speeding up the movement of food through the intestinal tract. Active ingredients in ginger include compounds called gingerols. Since ginger speeds up the passage of food and stool through the intestines, it's easy to understand why taking too much ginger could cause diarrhea. Diarrhea can occur when stool moves too rapidly through the gastrointestinal tract.
Like many herbs, ginger doesn't have a standardized dose. Because ginger also comes in a number of forms, including powder, liquid extract, capsules or fresh root, it makes standardization of dosing difficult. In general, do not take more than 4 grams of ginger per day, or you may have an increased risk of side effects such as diarrhea, according to the University of Maryland Medical Center. To treat morning sickness in pregnancy, take 250 milligrams four times a day only if your doctor gives you his approval, MedlinePlus recommends.
If you're taking ginger for stomach upset and develop diarrhea, don't assume ginger is causing the diarrhea. A number of medical conditions can also cause stomach upset and diarrhea; some may require medical treatment to improve. Call your doctor if you have diarrhea that doesn't stop when you stop taking ginger. Use of ginger in pregnancy is also controversial, although the risk of fetal malformation in women who take ginger appears to be the same as in the general population, between 1 and 3 percent, according to MedlinePlus.
Other Side Effects
Ginger can cause other gastrointestinal side effects in addition to diarrhea. Heartburn, burping or mouth or throat irritation can also occur. Other side effects include possibly lowering blood sugar levels or increasing the risk of bleeding, especially if you take blood thinners. The University of Maryland Medical Center recommends that you do not take ginger if you have gallstone, are scheduled for surgery or are pregnant.