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.

Amoebiasis

Amoebiasis is an infection that affects the gastrointestinal tract of humans. Amoebiasis is a common infection caused by a parasite that infects the large intestines of humans. People at any age can be infected with this disease, although it may be more common in young adults and middle-aged individuals. People who have this condition may or may not suffer from noticeable symptoms. Those who experience symptoms may be carrying one of two kinds of this disease: intestinal amoebiasis and extraintestinal amoebiasis.