You may also have diarrhea or a fever. It is sometimes called stomach flu, but it is not the flu. Germs like viruses and bacteria can cause it. You can catch it from someone else who has it, or you can get it from food poisoning. Food poisoning can happen if you eat foods that contain harmful germs.
The circular muscle located at the entrance and exit to the stomach is called the sphincter. So for this question, you are talking about two distinct sphincters. This anatomical structure is able to open, and contract or close as needed.
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral (front and side) abdominal wall which is deep to (layered below) the internal oblique muscle.he transverse abdominal, so called for the direction of its fibers, is the innermost of the flat muscles of the abdomen, being placed immediately beneath the internal oblique muscle.