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 The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn.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.
Sometimes, the stomach gas is held on to by the body. This can lead to cramping, abdominal pain and a distended abdomen. Abdominal gas is typically caused by diet, where gas producing foods are consumed in abundance. In fact, a buildup of abdominal gas whether, a byproduct of chewing gum and bloating or a meal comprised of beans is one of the most common causes of stomach pain.