Snails and Slugs: Phylum Mollusca, Class Gastropoda. The Class Gastropoda (in Phylum Mollusca) includes the groups pertaining to snails and slugs. The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn. The shell of these creatures is often what is recovered in a fossil dig.
Causes of bleeding in the stomach can include: 1  Ulcers: Ulcers may enlarge and erode through a blood vessel, causing bleeding. 2  Gastritis. 3  Cancer. Gastric varices.  Dieulafoy 1  lesions. Portal gastropathy.
Weakness in your stomach lining allows digestive juices to damage and inflame it, causing gastritis. Learn more about causes, diagnosis, and treatment. Weakness in your stomach lining allows digestive juices to damage and inflame it, causing gastritis. Having a thin or damaged stomach lining raises your risk for gastritis. A gastrointestinal bacterial infection can also cause gastritis. The most common bacterial infection that causes it is Helicobacter pylori.