Stomach

The stomach is a muscular, hollow, dilated part of the digestion system which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects (mid-gut), and molluscs. It is involved in the second phase of digestion, following mastication (chewing).
The stomach is located between the esophagus and the small intestine. It secretes protein-digesting enzymes and strong acids to aid in food digestion, (sent to it via oesophageal peristalsis) through smooth muscular contortions (called segmentation) before sending partially digested food (chyme) to the small intestines.

Infection in abdoman

An abdominal infection is an infection which occurs in the abdomen, the area of the body between the thorax and the pelvis. There are a number of causes of abdominal infection, ranging from ruptured organs to surgical procedures, and these infections can be life-threatening if not treated promptly and aggressively. Treatment plans often include hospitalization, since the patient needs to be carefully monitored.