Stomach is an organ between oesophagus and small intestine. It is where digestion of protein begins. The stomach has three tasks. It stores swallowed food. It mixes the food with stomach acids. Then it sends the mixture on to the small intestine.

Most people have a problem with their stomach at one time or another. Indigestion and heartburn are common problems. You can relieve some stomach problems with lifestyle changes, such as avoiding fatty foods or eating more slowly. Other problems like peptic ulcers or GERD require medical attention.

You should see a doctor if you have any of the following:

• Blood when you have a bowel movement

• Severe abdominal pain

• Heartburn not relieved by antacids

• Unintended weight loss

• Ongoing vomiting or diarrhoea

Gastritis occurs when the lining of the stomach becomes inflamed or swollen.

Gastritis can last for only a short time (acute gastritis). It may also linger for months to years (chronic gastritis).

Causes

The most common causes of gastritis are:

• Certain medicines, such as aspirin, ibuprofen, or naproxen and other similar drugs

• Heavy alcohol drinking

• Infection of the stomach with a bacteria called Helicobacter pylori

Less common causes are:

• Autoimmune disorders (such as pernicious anemia)

• Backflow of bile into the stomach (bile reflux)

• Cocaine abuse

• Eating or drinking caustic or corrosive substances (such as poisons)

• Extreme stress

• Viral infection, such as cytomegalovirus and herpes simplex virus (more often occurs in people with a weak immune system)

Trauma or a severe, sudden illness such as major surgery, kidney failure, or being placed on a breathing machine may cause gastritis.

A peptic ulcer is a sore in the lining of your stomach or your duodenum, the first part of your small intestine. A burning stomach pain is the most common symptom. The pain:

• Starts between meals or during the night

• Briefly stops if you eat or take antacids

• Lasts for minutes to hours

• Comes and goes for several days or weeks

Peptic ulcers happen when the acids that help you digest food damage the walls of the stomach or duodenum. The most common cause is infection with a bacterium called Helicobacter pylori. Another cause is the long-term use of nonsteroidal anti-inflammatory medicines (NSAIDs) such as aspirin and ibuprofen. Stress and spicy foods do not cause ulcers, but can make them worse.

Overview

A hiatal hernia occurs when the upper part of your stomach bulges through the large muscle separating your abdomen and chest (diaphragm).

Your diaphragm has a small opening (hiatus) through which your food tube (esophagus) passes before connecting to your stomach. In a hiatal hernia, the stomach pushes up through that opening and into your chest.

A small hiatal hernia usually doesn't cause problems. You may never know you have one unless your doctor discovers it when checking for another condition.

But a large hiatal hernia can allow food and acid to back up into your esophagus, leading to heartburn. Self-care measures or medications can usually relieve these symptoms. A very large hiatal hernia might require surgery.

Symptoms

Most small hiatal hernias cause no signs or symptoms. But larger hiatal hernias can cause:

• Heartburn

• Regurgitation of food or liquids into the mouth

• Backflow of stomach acid into the esophagus (acid reflux)

• Difficulty swallowing

• Chest or abdominal pain

• Feeling full soon after you eat

• Shortness of breath

• Vomiting of blood or passing of black stools, which may indicate gastrointestinal bleeding

When to see a doctor

See your doctor if you have any persistent signs or symptoms that worry you.

Causes

A hiatal hernia occurs when weakened muscle tissue allows your stomach to bulge up through your diaphragm. It's not always clear why this happens. But a hiatal hernia might be caused by:

• Age-related changes in your diaphragm

• Injury to the area, for example, after trauma or certain types of surgery

• Being born with an unusually large hiatus

• Persistent and intense pressure on the surrounding muscles, such as while coughing, vomiting, straining during a bowel movement, exercising or lifting heavy objects

Risk factors

Hiatal hernias are most common in people who are:

• Age 50 or older

• Obese

Have you ever had the "stomach flu?" What you probably had was gastroenteritis - not a type of flu at all. Gastroenteritis is an inflammation of the lining of the intestines caused by a virus, bacteria, or parasites. Viral gastroenteritis is the second most common illness in the U.S. The cause is often a norovirus infection. It spreads through contaminated food or water or by contact with an infected person. The best prevention is frequent hand washing.

Viral gastroenteritis is an intestinal infection marked by watery diarrhea, abdominal cramps, nausea or vomiting, and sometimes fever. The most common way to develop viral gastroenteritis — often called stomach flu —is through contact with an infected person or by ingesting contaminated food or water.

The most common problem with gastroenteritis is dehydration. This happens if you do not drink enough fluids to replace what you lose through vomiting and diarrhoea. Dehydration is most common in babies, young children, older adults, and people with weak immune systems.

Stomach cancer is cancer that starts in the stomach.

Causes

Several types of cancer can occur in the stomach. The most common type is called adenocarcinoma. It starts from one of the cell types found in the lining of the stomach.

Adenocarcinoma is a common cancer of the digestive tract. It is not very common in the United States. It is diagnosed much more often in people in eastern Asia, parts of South America, and eastern and central Europe. It occurs most often in men over age 40.

The number of people in the United States who develop this cancer has decreased over the years. Experts think this decrease may be in part because people are eating less salted, cured, and smoked foods.

You are more likely to be diagnosed with gastric cancer if you:

• Have a diet low in fruits and vegetables

• Have a family history of gastric cancer

• Have an infection of the stomach by a bacteria called Helicobacter pylori ( H pylori)

• Had a polyp (abnormal growth) larger than 2 centimeters in your stomach

• Have inflammation and swelling of the stomach for a long time (chronic atrophic gastritis)

• Have pernicious anemia (low number of red blood cells from intestines not properly absorbing vitamin B12)

• Smoke