Peppermint.

Peppermint Relieves IBS Pain and May Reduce NauseaPeppermint has a long history of use in folk medicine and aromatherapy.
As is the case with many herbs, it is the oily component that contains the agents responsible for the health effects.
Many studies have shown that peppermint oil can improve pain management in irritable bowel syndrome, or IBS (16, 17, 18).
It appears to work by relaxing the smooth muscles in the colon, which relieves pain experienced during bowel movements. It also helps to reduce abdominal bloating, which is a common digestive symptom (19, 20).
There are also some studies showing that peppermint in aromatherapy can help fight nausea.
In a study of over 1,100 women in labor, peppermint aromatherapy caused significant reductions in nausea. It has also been shown to reduce nausea after surgery and C-section births (21, 22, 23, 24).