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 The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn.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.
Crohn's disease, colon cancer, or any disease that causes intestinal obstruction, may also cause abdominal bloating. Internal hernias or adhesions (scar tissue) from surgery may cause bloating or pain. Fatty foods can delay stomach emptying and cause bloating and discomfort, but not necessarily too much gas.