What is gastritis?
Gastritis is a general term used to describe inflammation of the mucosa (lining) of the stomach. It is not a single disease, but a group of disorders that have inflammatory changes in the gastric mucosa in common, but which have different clinical features and causes.
There are several classifications of gastritis. The most commonly used are based on:
- How acute or chronic the clinical process is
- Where in the gut the gastritis occurs
- The histological characteristics of the gastritis. Histology is the study of the structure of tissues which are delineated using special staining techniques and examined under a microscope
- The proposed causes of the two main types of chronic gastritis
Based on the clinical features of gastritis, the two main forms, which are very different from each other, are acute gastritis and chronic gastritis.
The main form of acute gastritis is called acute haemorrhagic, or acute erosive, gastritis. This reflects the fact that in this form of the disease there is bleeding from the gastric mucosa. The mucosa also erodes as a result of the associated inflammation.
What causes acute haemorrhagic gastritis?
This type of gastritis can develop for no apparent reason. However, it is more likely to be associated with:
- Patients in medical or surgical intensive care who have suffered severe trauma, major surgery, massive shock, burns, failure of the respiratory, kidney or liver systems, or severe infection with septicaemia. In these cases it is sometimes called stress-induced gastritis.
- Drugs such as aspirin and other non-steroidal anti-inflammatories
- Increased production of bile acids, or of digestive enzymes from the pancreas
- Alcohol abuse
What are the signs and symptoms of acute haemorrhagic gastritis?
Bleeding from the gastric mucosa in acute gastritis can result in sudden and dramatic blood loss or haemorrhage. It can also cause subtle bleeding which may be detectable only by examining the stool for blood, or through the development of mild and otherwise unexplained anaemia.
Obvious symptoms and signs include:
- Vomiting blood – which often appears as altered blood, looking like 'coffee grounds'
- Passing blood in the stools – again as altered blood resulting in foul-smelling, black, tarry stools. These are called melaena stools
Less common symptoms and signs include:
- Pain in the upper part of the abdomen
Pain is much less common in acute haemorrhagic gastritis than in ulcer disease.
A physical examination is usually normal in patients with acute haemorrhagic gastritis. It may show:
- Tenderness in the upper part of the abdomen
- Evidence of blood loss in that they are pale, have a fast heart beat (tachycardia) and low blood pressure
How is acute haemorrhagic gastritis diagnosed?
The presence of bleeding is usually first suspected after blood has been detected in the stool or vomitus.
Diagnosis is established by examining the stomach with a flexible fibre-optic endoscope, through which the specialist can see haemorrhage in the mucosa and other changes that are characteristic of the condition.
How is acute haemorrhagic gastritis treated?
Treatment should be directed to:
- Preventing the development of haemorrhagic gastritis by giving hourly antacids to severely ill patients, stopping offending drugs and limiting alcohol intake
- Treating the associated disease
- Withdrawal of any offending drug, such as non-steroidal anti-inflammatories
- General supportive measures in the case of severe haemorrhage, such as maintenance of oxygen, blood volume (by transfusion where necessary) and fluid and electrolyte requirements
What is the outcome of acute haemorrhagic gastritis?
In the less common cases where the patient has bled very heavily, mortality is generally more than 60%.
However, less severe forms of the illness respond well to measures such as regular antacids, correction of blood and fluid volume and general supportive measures.
Chronic gastritis is a different entity to acute gastritis. The inflammation in the stomach is caused by specific inflammatory cells that are generally present in chronic inflammation. It is often patchy and irregular in distribution.
The classification of chronic gastritis
Chronic gastritis has been divided into two major forms – type A and type B.
Type A chronic gastritis is less common. It characteristically involves only two particular parts of the stomach, the fundus and the larger, lower portion.
This is the form of gastritis that can lead to pernicious anaemia, a form of anaemia involving a deficiency of vitamin B12. This is a result of the body's failure to produce a substance called intrinsic factor, which allows the absorption of vitamin B12 from the gut.
Type B gastritis is much more common. In younger patients this type of chronic gastritis usually involves only a part of the stomach called the antrum. In older patients the entire stomach is affected.
There is a strong association of the bacterium Helicobacter pylori with type B gastritis. Eradication of H. pylori produces improvement in the histological changes associated with this type of gastritis. When treatment is stopped, the changes recur and the bacteria reappear.
What causes chronic gastritis?
Secretion of acid in the stomach is reduced in both type A and type B gastritis, which contributes to the inflammatory process that causes the disorders.
There is no good evidence that the acute injury to the gastric mucosa, which is associated with stress or with alcohol or non-steroidal anti-inflammatory drugs, leads to chronic gastritis.
Acute gastritis caused by H. pylori may lead to type B chronic gastritis over time.
How is chronic gastritis diagnosed?
The most reliable means of diagnosing, identifying and classifying chronic gastritis is through biopsy of the gastric mucosa. This involves using a flexible fibre-optic endoscope to view the inside of the stomach. A small sample of the mucosa is then clipped off, stained histologically and then examined under a microscope.
How is chronic gastritis treated?
There is no specific treatment for type A or type B chronic gastritis. The exception is the form that causes pernicious anaemia, which requires life-long replacement of vitamin B12.
Uncommon specific gastritis syndromes
This disease of unknown cause results in very large, thick folds in the mucosa of the stomach. It generally affects adults aged between 30 and 60. It is usually chronic, but can resolve spontaneously. The symptoms may include loss of appetite, pain in the upper part of the abdomen and swelling around the eyes and in the legs. The disease causes loss of protein in the serum – the watery part of the blood.
This is a condition in which there is extensive infiltration of the gastric mucosa with cells called eosinophils. These are cells produced by the immune system in response to foreign bodies present in the body. This often results from severe infestation with parasitic nematode worms.
Physical causes of gastritis
These include ingestion of corrosive materials and radiation. Infectious (septic) gastritis can develop following damage by physical agents. Bacteria invade the inflamed mucosa, causing a serious illness that may result in death.
Other causes of gastritis
People who are debilitated by cancer or HIV may develop viral or fungal gastritis with Candida, histoplasmosis (an infection caused by the spores of the fungus Histoplasma capsulatum), cytomegalovirus and mucormycosis.
When to call your doctor
If you or any member of your family develop any of the symptoms listed above, seek medical advice.
In general, a doctor should be seen as a matter of urgency if any of the following symptoms develop:
- Vomiting 'coffee ground' liquid
- Passing foul-smelling, tarry, black stools
- Severe upper abdominal pain, with vomiting and nausea
- Chronic fatigue, loss of appetite and swelling around the eyes or in the legs
(Reviewed by Prof. Don du Toit, University of Stellenbosch)
The information provided in this article was correct at the time of publishing. At Mediclinic we endeavour to provide our patients and readers with accurate and reliable information, which is why we continually review and update our content. However, due to the dynamic nature of clinical information and medicine, some information may from time to time become outdated prior to revision.