Peppermint and ginger are both things that help settle an upset stomach. I would suggest looking into a quality loose tisane (or even making your own) with one or both of these two things because the teabags you buy in the store are either going to be flavored, old or just bad quality.
OID - Medication once a day [Internet]; August 7, 2016 [cited 2016 AUG 7]. Available from: https://www.allacronyms.com/OID/Medication_once_a_day. 'OID - Medication once a day', All Acronyms, 7 August 2016, <https://www.allacronyms.com/OID/Medication_once_a_day> [accessed 7 August 2016] All Acronyms, OID - Medication once a day (Aug. 7, 2016, 4:08 PM), available at https://www.allacronyms.com/OID/Medication_once_a_day.
If your doctor instructs you to take a drug twice a day, for example, the pharmacist can choose to write twice a day, every 12 hours, once in the morning and once in the evening, or similar instructions.