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 The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn.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.
Internal bleeding may be caused as a side effect of medications (most often from nonsteroidal anti-inflammatory drugs such as ibuprofen and aspirin) and alcohol. These substances can cause inflammation and bleeding of the esophagus, stomach, and duodenum, the first part of the small intestine as it leaves the stomach.