Hi - peppermint oil caps are one of my favorite things for preventing IBS attacks in the first place, but they also require some care when you're using them. If you don't follow the directions not only will they not help you, you might also give yourself heartburn.
Peppermint is contraindicated for people with GERD/Reflux/chronic heartburn. Many people with IBS often have these conditions, so we worked around it by enteric coating the peppermint oil capsules. This helps them to pass through the stomach without dissolving by making them resistant to the stomach acid.
In fact, we doubled the enteric coating on our peppermint caps because we found it helped people with these conditions to be able to use them to manage their IBS without aggravating their upper GI issues.
However, some people with severe GERD/Reflux/chronic heartburn still have problems with the peppermint capsules because they will dissolve in the stomach before reaching the intestines. The antispasmodic effect you want to happen in your intestines will then occur in the stomach and this relaxes the sphincters at the top of the stomach. If this happens, it can lead to heartburn.
There are a few things we have found that help to prevent this from happening.
1) Take the peppermint capsules on an empty stomach an hour before the meal to allow them time to reach the intestines and dissolve before the food arrives. Taking them too close to meal time can be problematic for people with reflux.
2)The peppermint caps should not be taken during or after a meal because the food will block them from reaching the intestines and this could cause them to dissolve in the stomach.
3) Drinking only enough liquid to swallow the capsules seems to help them pass through without dissolving in the stomach. The enteric coating makes them resistant to stomach acid, but they are still water soluble. Limiting the amount of liquid they'll be floating around in will help them reach their destination.
4) You shouldn't take them at the same time as any medication (prescription or over-the-counter) designed to lower the stomach acid. Lowering the stomach acid makes the enteric coating less likely to work (remember it is resistant to high acid). For folks who need to take these medications, what we came up with is taking the peppermint caps about an hour before you take the acid lowering/blocking medication. This will give them a better chance of making it down to the intestines where they will dissolve and start to take effect without affecting the upper GI.
On a related note, not being able to tolerate the enteric coated peppermint oil capsules because they are dissolving in the stomach and causing heartburn or peppermint burping might indicate low stomach acid. If the stomach acid is high enough, the caps should not dissolve until they reach the intestines where the acid is low. This means you shouldn't burp up anything or have any upper GI complications at all.
In naturopathic medicine, heartburn is often thought to be caused by low stomach acid which causes the undigested food to sit in the stomach too long and create pressure. It can also contribute to inadequately digested protein in the stomach. This can disrupt the digestive process downstream as well. If you followed the tips I listed above and still experienced heartburn, you might want to follow up with a provider to test your stomach acid levels.
Please note that the peppermint caps are meant to be used as a preventative measure. They do not work immediately, since you have to wait until your stomach is empty and they have to reach your intestines before they dissolve.
If you need immediate help for pain/spasms/cramps, use the Peppermint Tummy Tea instead. The peppermint caps are stronger, but the teas work faster.