The information provided here is not a replacement for a doctor. You shouldn't use it for the purpose of self-diagnosing or self-medicating but rather so you can have a more informed discussion with a professional TCM practitioner.
Because it is a herb specifically indicated to treat ulcer as can be seen on Cuttlebone's page.
Cuttlebones is a Warm herb that tastes Pungent and Salty. It targets the Spleen and the Kidney.
Its main actions are: Restrains and stops bleeding. Holds Essences and stops seminal discharge or leukorrhea. Clears Dampness and promotes wound heeling. Inhibit gastric secretion and stops pain.
Trauma bleeding Premature ejaculation Vaginal discharge Acid reflux Belching Stomach acidity Abdominal pain Rashes Loss of blood