to aid digestion and help minimize side effects of medication it's very important to drink enough liquids during the day. Herbal tea and infusions are a great way of getting hydrated - with extra benefits!
I'm not an expert at this, but I've been told that camomile is good for relaxation, and that ginger, willowbark and turmeric can be good for treating pain. By visiting a well supplied health food store you can look and smell at different infusions and blends, and choose those that appeal to you. Maybe there is a person there who knows about the benefits of different types of tea, and you can build your own little tea-pharmacy. After all, many effective pharmaceutical drugs are based on ancient herbal remedies.
According to wikipedia: "Many of the pharmaceuticals currently available to physicians have a long history of use as herbal remedies, including morphine, aspirin, digitalis, and quinine. The World Health Organization (WHO) estimates that 80 percent of the world's population presently uses herbal medicine for some aspect of primary health care."
Personally I'm a big fan of yogi tea spice infusions, and peppermint tea is a staple in my kitchen. For many years I have harvested peppermint from a plant that has grown wild in my mother's garden. It has spread in a whole area, so the supply is more than plentiful, I tie the stalks together and hang them to dry in the attic for a few weeks, then crush the dried leaves and have my own free supply of my favorite tea.