The digestive system

This is the system in charge of digesting food so as to obtain energy from it as well as the substances needed for the correct functioning of the body. It begins in the mouth and finishes in the anus.

Its parts include:

  1. Mouth. Mastication (or chewing) takes place, a process during which food is shredded and mixed with saliva.
  2. Pharynx. An organ through which food passes. It is located in the throat.
  3. Esophagus. It is also an organ through which food passes. It is located in the chest.
  4. Stomach. Important digestive organ. It secretes hydrochloric acid and pepsin which digests protein.
  5. Small intestine. Organ that takes part in the digestion and absorption of food. It is divided into three parts: duodenum, jejunum and ileum.
  6. Large intestine. Final portion of the intestine. It absorbs the active ingredients in food.
  7. Anus. Sphincter muscle that regulates defecation.

All the digestive system is lined internally with a mucous membrane.


Stomach. The stomach produces hydrochloric acid and pepsin which are held inside the stomach and aid in the digestion of food. Pepsin is an enzyme that digests protein in the acid environment created by the hydrochloric acid. The acid and the pepsin would damage the gastric membrane if for the fact that:

  1. The mucous membrane itself acts as a barrier against the action of hydrochloric acid and pepsin.
  2. The mucous membrane absorbs the excess acid and removes it through the blood flow.
  3. The gastric mucous membrane is self-repairing and maintains its integrity when it has been damaged.

Helicobacter pylori

Helicobacter pylori (H. pylori) is a bacteria. It seems to be responsible for most peptic ulcers. It is estimated that half the population has H. pylori. Although it is not completely clear how this bacteria is transmitted, it seems to pass through water or food. It has been found in the saliva of some people, so it may spread through kissing. Close contact with people infected with H. pylori and exposure to their vomit are other forms of transmission. Washing your hands after going to the bathroom and before eating is a simple but effective means of preventing the spread of H. pylori.

How is the presence of H. pylori diagnosed in a sick patient? It can be diagnosed by blood, breath and fecal tests.

How does H. pylori cause diseases? H. pylori weakens the defenses of the gastro-duodenal mucous membrane, making it sensitive to the action of gastric acid. H. pylori secretes enzymes that neutralize the acid and allow it to live in harsh environment of the stomach.

Acute gastritis

Acute gastritis is a necrotic-inflammatory lesion of the gastric mucous membrane.


Gastritis by external causes (exogenous)

The causes of gastritis can be bacterial, due to toxic and alcoholic substances, due to medicines, or due to caustic products. Gastritis with a bacterial origin is the most common form of gastritis. It occurs as a result of the ingestion of contaminated food. H. pylori may cause gastritis and peptic ulcers. Gastritis caused by drugs is usually produced by certain anti-inflammatory and analgesic medicines. They usually cause erosive gastritis which is the erosion of the gastric mucous membrane.

Gastritis by internal causes (endogenous)

Secondary gastritis due to infections and serious diseases.

What are the signs of gastritis?

Gastritis can be present without any symptoms, or on the other extreme, it may even involve an ulcer or gastric perforation. The most typical case is for the patient to have a general feeling of weakness, discomfort, pain or burning feelings in the epigastrium, a lack of appetite, nausea and vomiting.

How is gastritis diagnosed?

Physicians take into consideration the patient’s medical history and symptoms. He can also perform a radiological study and an endoscopy.


Rest and diet. Antacids are prescribed as needed.

Chronic gastritis

Although it is common, it may not manifest itself clinically. It is usually linked to H. pylori. There are several types of chronic gastritis. Its causes vary: H. pylori, autoimmune factors, substances that irritate the gastric membrane, and allergic factors to name a few. According to its morphology, there are two main types of chronic gastritis: atrophic and non-atrophic.

Chronic atrophic gastritis.

This disease starts with a superficial inflammation of the gastric mucous membrane. Then the glands of the membrane begin to atrophy and may even disappear. This results in a reduction in gastric secretions of acid and pepsin which in turn allows bacteria to colonize the stomach. This process may lead to stomach cancer.

Chronic non-atrophic gastritis.

There is no loss of gastric glands with chronic non atrophic gastritis.

What are the signs of chronic gastritis?

Patients with chronic gastritis may show no symptoms or may have a feeling of discomfort in the epigastric region, nausea and vomiting.


Your physician will run tests to see if H. pylori is present and if so, prescribe medicine to eliminate it. Other therapeutic measures include a controlled diet, the use of antacids, H-2 blockers and proton pump inhibitors.