Guayaba Leaves and Fruit

Psidium guajaba

Main actions: antidysenteric, antiseptic, antibacterial, antispasmodic,
cardiotonic (tones, balances, strengthens the heart)
Main uses: for dysentery (bacterial and amebic), diarrhea, colic, and infantile
rotavirus enteritis; as a broad-spectrum antimicrobial for internal and external
bacterial, fungal, candidal, and amebic infections; to tone, balance, protect
and strengthen the heart (and for arrhythmia and some heart diseases); as a
cough suppressant, analgesic (pain-reliever), and febrifuge (reduces fever)
for colds, flu, sore throat, etc; as a topical remedy for ear and eye infections.
Cautions: It has cardiac depressant effect and is contraindicated in some
heart conditions.

Guava may have been domesticated in Peru several thousand years ago; Peruvian archaeological sites have revealed guava seeds found stored with beans, corn, squash, and other cultivated plants. Guava fruit is still enjoyed as a sweet treat by indigenous peoples throughout the rainforest, and the leaves and bark of the guava tree have a long history of medicinal uses that are still employed today.

The Tikuna Indians decoct the leaves or bark of guava as a cure for diarrhea. In fact, an infusion or decoction made from the leaves and/or bark has been used by many tribes for diarrhea and dysentery throughout the Amazon, and Indians also employ it for sore throats, vomiting, stomach upsets, for vertigo, and to regulate menstrual periods. Tender leaves are chewed for bleeding gums and bad breath, and it is said to prevent hangovers (if chewed before drinking). Indians throughout the Amazon gargle a leaf decoction for mouth sores, bleeding gums, or use it as a douche for vaginal discharge and to tighten and tone vaginal walls after childbirth. A decoction of the bark and/or leaves or a flower infusion is used topically for wounds, ulcers and skin sores. Flowers are also mashed and applied to painful eye conditions such as sun strain, conjunctivitis or eye injuries.

Centuries ago, European adventurers, traders, and missionaries in the Amazon Basin took the much enjoyed and tasty fruits to Africa, Asia, India, and the Pacific tropical regions, so that it is now cultivated throughout the tropical regions of the world. Commercially the fruit is consumed fresh or used in the making of jams, jellies, paste or hardened jam, and juice. Guava leaves are in the Dutch Pharmacopoeia for the treatment of diarrhea, and the leaves are still used for diarrhea in Latin America, Central and West Africa, and Southeast Asia. In Peruvian herbal medicine systems today the plant is employed for diarrhea, gastroenteritis, intestinal worms, gastric disorders, vomiting, coughs, vaginal discharges, menstrual pain and hemorrhages, and edema. In Brazil guava is considered an astringent drying agent and diuretic and is used for the same conditions as in Peru. A decoction is also recommended as a gargle for sore throats, laryngitis and swelling of the mouth, and used externally for skin ulcers, and vaginal irritation and discharges.

This information is gathered directly from:
https://rain-tree.com/guava.htm