It plays a vital role in digestion of foods, releases various enzymes and also protects the lower intestine from harmful organisms.

[citation needed] The stomach lies in the upper part of the abdomen just below the left rib cage.

This may result in upper abdominal pain, indigestion, loss of appetite, nausea, vomiting and heartburn.

If the bleeding is rapid and of adequate volume it may even result in vomiting of bright red blood (hematemesis).

When the acidity is uncontrolled, it can even cause severe blood loss (anemia) or lead to perforation (hole) in the stomach which is a surgical emergency.

The most common cause of gastroparesis is diabetes but it can also occur from a blockage at the distal end of stomach, a cancer or a stroke.

Its main feature is inflammatory ulcers that can affect the total thickness of the stomach wall and can bleed but rarely perforate.

Stomach cancers usually occur due to fluctuations in acidity level and may present with vague symptoms of abdominal fullness, weight loss and pain.

The actual cause of stomach cancer is not known but has been linked to infection with Helicobacter pylori, pernicious anemia, Menetriere's disease, and nitrogenous preservatives in food.

The procedure does require intravenous sedation and takes about 30–45 minutes; the endoscope is inserted via the mouth and can visualize the entire swallowing tube, stomach and duodenum.