Diarrhea is caused by toxins produced by germs that colonize on the lining of the intestinal tract. Guava has proved to be beneficial to individuals suffering from Diarrhea. Guava is rich in astringents which help to binds up loose bowels in diarrhea. These astringents are alkaline in nature and have disinfectant and anti-bacterial properties, and thus help to cure dysentery by inhibiting microbial growth and removes extra mucus from the intestines. These properties and ingredients of guava also support healing in cases of gastroenteritis.

Guava is an excellent source of dietary fiber. High amount of dietary fiber present in guava helps prevent constipation. Guava provides 36 percent of the recommended daily value for dietary fiber. Also, the seeds of guava are effective laxatives. These attributes help in the formation of bowels and the cleaning up of the excretory system.

Juice of raw and immature guavas or decoction of guava-leaves bring relief to individuals suffering from cough and cold, reducing mucus, disinfecting the respiratory tract, throat and lungs and inhibiting microbial activity due to its astringent properties. Guava is one of richest in vitamin-C and iron which provide protections against cold and viral infections. If you have cold and cough it's good to go for the raw guava. The iron and vitamin C content in guava helps to prevent cold and keep viral infections at bay.

The astringents of guava enhance the skin texture and tighten loosened skin more than the beauty creams or skin toner gels can do. This is chiefly due to the abundance of astringents in its fruits and in leaves. Guava improves skin by using immature leaves and raw fruit on a decoction and washing the skin with it will give you a shiny skin. The astringents found in the fruit improve the skin texture and keep skin problems away.

: Guava forms an essential component of a weight loss diet with their intake of proteins, vitamins and fiber. Guava, being very high in roughage and very rich in vitamins, proteins and minerals, but with no cholesterol and less digestible carbohydrates, is very filling and satisfies appetite very easily. A medium sized guava for lunch is enough to supply nutrition till dinner.

The Vitamin C content of a common guava is about four times than of orange. Thus, guavas are effective remedies for scurvy, which is characterized by swollen and bleeding gums due to deficiency of Vitamin C.

Guava is an excellent source of the cancer-fighting antioxidant, lycopene. Lycopene in guava is easily absorbs than lycopene from tomato by our body due to the difference in the cell structure that allows the antioxidant to be absorbed whether the fruit is raw or cooked. Lycopene consumption is associated with significantly lower rates of prostate cancer, and it has also been found to inhibit the growth of breast cancer cells. Lycopene promotes good health by the influence of "free radicals" that can damage cells and can contribute to developing cancer and coronary heart disease. All varieties of guava are loaded with antioxidants but the one with the red flesh type contains more than the white-fleshed apple guava. Since guava has lycopene antioxidant, it helps prevent prostate cancer.

Guavas does not contain iodine. They are good sources of copper, plays a role in thyroid metabolism especially in hormone production and absorption.

Guava is safe when eaten as food, but there's not enough information to know if it's safe in the larger amounts that are used as medicine. If you are pregnant or breast-feeding, stick with food amounts until more is known.