I think Black Tea is probably a good remedy for various things, however for me it always upsets my stomach. It either acts as a laxative, gives me terrible gas that feels like I swallowed a bag of knives, or both. Take a small dose to see how it affects you before trying it as a remedy.
I'm responding to the claim that black tea cures an upset stomach. Whenever I drink black tea, I always develop painful gas and bloating and sometimes diarrhea. My grandmother said she has the same problem and that it may be caused by tannins in the tea. Maybe some people just aren't able to break down the chemicals? What does help me when i get a "gas attack" is to get on my knees and stick my butt in the air, focusing on relaxing my abdominal muscles. The posture is a bit ridiculous, but it does help expel the gas after a couple minutes. For an upset stomach, i make a tea of grated ginger, mint, chamomile, or a combination. to that i add organic milk and honey.