Cinnamon Sticks (Cassia)

The Cassia pulp is a popular laxative and is used in the treatment of constipation. It can be safely taken even by children and expectant mothers. The pulp of Cassia is a mild pleasant and safe purgative. Approximately four grams of the pulp is taken with an equal quantity of sugar or tamarind.

The root of the Cassia tree is a tonic and useful in reducing fever. An alcoholic extract of the root bark is used for black water fever. The root of Cassia is useful in common cold. In case of running nose smoke from the burning root can be inhaled. It encourages a copious nasal discharge and provides relief.

The leaves of the Cassia tree are helpful in relieving irritation of the skin and in alleviating swellings and pains. Their juice or paste serves as a useful dressing for ringworm and inflammation of the hands or feet caused by exposure to cold. They also relieve dropsically swellings due to excessive accumulation of fluid in the body tissue. Its leaves can be rubbed beneficially on affected parts for relief from rheumatism and facial paralysis.

Cassia also has a significant amount of the blood-thinning phytochemical coumarin which has led Germany to ban its importation.

Potential Health Benefits of Cassia and true Cinnamon vary. If buying for medical use please be sure you are buying the right product.
Cassia cinnamon is generally safe when used in amounts commonly found in foods and in medicinal doses.
Cassia has a significant amount of the blood-thinning phytochemical coumarin. In people who are sensitive coumarin might cause or worsen liver disease. Large amounts of cassia cinnamon should not be taken for a long period of time. People with liver disease should also avoid taking cassia cinnamon products. When applied to the skin cassia cinnamon can sometimes cause skin irritation and allergic skin reactions

sources
https://en.wikipedia.org/wiki/Cinnamon_bark
https://homecooking.about.com/od/cookingfaqs/f/faqcassia.htm
https://www.home-remedies-guide.com/herbs/Cassia.htm