What is the stomach?
The human stomach is a walled sac that is a part of the alimentary tract lying between the esophagus (food pipe) and duodenum (first part of the small intestine). It plays a central role in both mechanical and chemical digestion of food – the process of breaking down food into simpler compounds for absorption into the body.
What is a stomach problem?
The term stomach problem is broadly used to describe any disorder relating to the stomach. It is also commonly used quite loosely to describe upper gastrointestinal symptoms in general. However, these symptoms may not be emanating from the stomach or be associated with any stomach disorder. The word ‘stomach’ is also at times used to refer to the abdomen in general. In this context, stomach problems may also refer to abdominal problems at large.
Stomach Problem Meaning
It is important to know the basic structure, activity and functions of the stomach in order to understand what may be meant by the term ‘stomach problem’. It is used to describe any upper abdominal symptoms, particularly with discomfort or pain that is left sided, any symptoms shortly after eating or when hungry. Although the symptoms are indicative of a gastrointestinal disturbance, some symptoms like pain is non-specific and may be related to surrounding structures. Technically a stomach problem refers to any disturbance or disease of the stomach. However the stomach does not exist in isolation in the alimentary tract and there can be an overlap of diseases although it is attributed mainly to the stomach.
The stomach is a dilated portion of the alimentary tract that leads from the esophagus. The four main parts of the stomach are the :
- Cardia at the entrance of the stomach.
- Fundus which is the dilated upper portion of the stomach next to the cardia.
- Body which is the largest section of the stomach lying between the parts at either end.
- Pylorus which is at the end of the stomach leading into the duodenum.
Food travels down the esophagus, is then allowed into the stomach by relaxation of the lower esophageal sphincter (LES) and enters the body of the stomach where it undergoes chemical and mechanical digestion. The pylorus carefully regulates the outflow of partially digested food by the action of the pyloric pump.
The stomach is located in the left upper abdominal quadrant. It lies immediately beneath the diaphragm which separates the stomach in the abdominal cavity from the left lung in the thoracic cavity. Due to its position, a significant portion of the stomach is tucked in under the left ribcage particularly when lying down flat. It is pushed downwards when breathing by the contracted diaphragm and when standing upright due to gravity. The lower portion of the stomach extends across the midline to meet with the small intestine. Therefore the stomach mainly occupies the left upper quadrant, specifically the left hypochondrium, epigastric, umbilical and left lumbar (flank) regions of the abdomen.
The stomach has a multi-layered wall that is largely similar to the rest of the alimentary tract in that it has an inner secretory layer and a middle muscular layer to perform its relevant functions. Surrounding connective tissue provides the stomach with it flexibility and strength of its walls. The inner lining of the stomach is known as the gastric mucosa. There are three important types of cells that make up the mucosa which contribute to the stomach’s functions and protective mechanisms.
- Parietal cells (oxyntic cell) which produce hydrochloric acid (HCl).
- Chief cells (peptic cell) which produce digestive enzymes like pepsin (inactive ~ pepsinogen).
- Goblet cells or mucus neck cells which produce large amounts of mucus.
The stomach is responsible for both mechanical and chemical digestion. Strong muscular contractions churn food, thereby breaking it down, while mixing it with the acid and digestive enzymes. The chemical action of these substances then break down the food even further into simpler nutrients. Eventually the liquid substance with small chunks of food known as gastric chyme is pushed out into the duodenum of the small intestine where it undergoes further digestion and from where most of the nutrients are absorbed into the bloodstream.
The inner lining of the stomach is protected from the highly corrosive stomach acid and digestive enzymes by a film of mucus. This barrier is the reason why the stomach can hold such corrosive substances yet not be digested by it. The mucus cells of the stomach are constantly producing and secreting mucus to ensure that this barrier is maintained. These cells are in large numbers within the cardia, fundus and pylorus of the stomach. It also provides some degree of lubrication for the stomach contents particularly as it is being churned by the strong muscle contractions of the stomach wall.
Types of Stomach Problems
The stomach as with any part of the body is prone to various diseases which can give rise a variety of symptoms. The main types of diseases include inflammation, infections, abnormal tissue growth or changes in stomach activity.
- Inflammation of the stomach wall – gastritis.
- Infection – H.pylori infection and infectious gastroenteritis.
- Growths – polyps, benign tumors and cancer.
- Excessive stomach acid – Zollinger-Ellison syndrome.
- Diminished stomach acid – hypochlorhydria or achlorhydria.
- Delayed gastric emptying -gastroparesis.
A common problem that is sometimes attributed to the stomach is gastroesophageal reflux disease (GERD) which is acid reflux. Here the backward flow of stomach acid into the esophagus causes esophageal irritation with symptoms like heartburn and nausea. GERD, however, is not usually a stomach problem but rather a problem with the esophagus and particularly the lower esophageal sphincter (LES) which should normally prevent this backward flow of stomach contents into the esophagus.
Stomach Problem Causes
Various causes may give rise to the different types of stomach problems mentioned above. However, some of the common causes include :
- H.pylori infection
- Stomach trauma – mechanical, chemical or electromagnetic (radiation)
- Excessive use of NSAIDs (non-steroidal anti-inflammatory drugs)
- Excessive alcohol consumption
- Advancing age
- Autoimmune disorders
- Vitamin B12 deficiency
- Crohn’s disease (inflammatory bowel disease)
- Stomach surgery, specifically removal (resection) of a portion of the stomach (gastrectomy).
Stomach Problem Symptoms
Stomach problems may be asymptomatic (no symptoms present) for long periods of time. When symptoms do become apparent, it may include :
- Discomfort or pain particularly in the left upper abdominal quadrant
- Vomiting, including vomiting of blood (hematemesis)
- Sensation of fullness (bloating)
- Stomach noises (borborygmi)
- Changes in appetite – hunger or lack of appetite (anorexia)
- Excessive belching
- Abdominal distention (rare)
- Bleeding from the stomach may present as dark blood in the vomit (hematemesis) or black tarry stool (melena)
Stomach Problem Treatment
The treatment of a stomach problem largely depends on the underlying causes. Some of the therapeutic measures includes :
- Proton pump inhibitors (PPIs) and H2-blockers which reduce stomach acid production and output.
- Antacids which neutralize the stomach acid.
- Metoclopramide which speeds up gastric emptying.
- Sucralfate which lines the stomach and protects it.
Surgery may involve the surgical removal of diseased tissue like polyps and other tumors or cancerous tissue. Surgical removal of the stomach is known as gastrectomy and may be partial or complete.
The wall of the stomach is prone to inflammation as with any part of the body and usually this affects only the inner layers that are in close contact with the stomach. It is caused by any factor that compromises the integrity of the mucus barrier that protects the inner lining of the stomach from the corrosive acid and enzymes contained within it.
Stomach inflammation definition
Inflammation of the stomach wall is known as gastritis. It is usually limited to the superficial layers of the stomach wall but severe cases can extend to the deeper layers or affect the entire thickness of the wall. Gastritis is one of the most common stomach problems and can be erosive or non-erosive. Erosive gastritis indicates inflammation where the lesions erode into the layers of the stomach wall. Non-erosive gastritis is the irritation and inflammation of the inner stomach layers usually without any destruction of tissue and formation of open sores (ulcers).
Stomach inflammation causes
- Helicobacter pylori infection (bacteria)
- Other infections caused by bacteria or its toxins alone, viruses, fungi and parasites.
- Medication particularly NSAIDs such as aspirin and ibuprofen, certain types of antibiotics and corticosteroids.
- Alcohol abuse.
- Bile reflux where the bile from the duodenum of the small intestine flows backward into the stomach.
- Stress – severe illnesses, after major surgery, or extensive acute injuries like burns.
- After a gastrectomy.
- Autoimmune disorders and immune-mediated reactions like in eosinophilic gastritis.
- Pernicious anemia related to vitamin B12 deficiency.
Stomach inflammation symptoms
Gastritis may be acute or chronic. The latter is largely asymptomatic except for periods of acute inflammation and related symptoms. The symptoms of gastritis which may vary depending on the severity includes :
- Gnawing dull ache or burning pain in the stomach area
- Hematemesis – blood in the vomit which usually has a dark brown coffee ground appearance
- Sensation of fullness
- Excessive belching
- Lack of appetite
- Melena – dark tarry stools due to the presence of blood
Stomach inflammation treatment
The main drugs for treating gastritis are stomach acid suppressing drugs like proton pump inhibitors (PPIs) and H2 blockers. Antacids remain the most popular over-the-counter drug and acts by neutralizing the stomach acid. Eradication therapy for an H.pylori infection requires the use of antibiotics.
The stomach is prone to infection in much the same way as any other part of the body. Invading pathogens mainly reach the stomach by the way of the alimentary tract through food and drink. The stomach acid usually destroys most of these pathogens but an infection is nevertheless a possibility.
Stomach infection definitions
Helicobacter pylori infection is a type of infection where the H.pylori bacteria attaches to the stomach wall, irritating the stomach lining and exposing it to the highly acidic environment by compromising the mucus barrier of the stomach. This type of infection is usually chronic and the bacteria has natural mechanisms to counteract the stomach acid.
Gastroenteritis is an infection of the stomach and intestines caused mainly by viruses, bacteria or bacterial toxins without live bacteria being present. It is known by common names such as the stomach flu and food poisoning. Most cases are acute in nature and may occur as outbreaks in certain areas.
Stomach infection causes
Helicobacter pylori is the bacteria that causes H.pylori infection. It can be passed from person to person through direct contact with saliva, sharing contaminated drinking water and fecal matter. It can also be spread through other vectors that have not as yet been clearly identified but are related to people living together particularly in overcrowded settings.
Gastroenteritis is mainly viral or bacterial in nature although certain parasites, particularly protozoa, may also be responsible at times. Viral gastroenteritis is most commonly caused by rotavirus and norovirus. Other types of viruses like the calcivirus, astrovirus and adenovirus may also be responsible particularly for infantile gastroenteritis. Bacterial gastroenteritis is commonly caused by Escherichia coli (E.coli), Staphylococcus aureus, Shigella, Salmonella, Campylobacter and Yersinia species. Spread through contaminated food and water are the main modes of transmission and is also associated with poor hygiene, sanitation, food storage practices and overcrowded living conditions.
Stomach infection symptoms
H.pylori infection leads to gastritis which can then complicate to peptic ulcers. The signs and symptoms of these conditions may therefore be an indication of an H.pylori infection.
Gastroentritis typically presents with :
- Abdominal cramps
- Excessive belching and/or flatulence
- Fever (sometimes)
- Abdominal distention
Stomach infection treatment
H.pylori infection requires eradication therapy with antibiotics and simultaneous use of acid suppressing drugs. Sucralfate may be used to assist with the healing of peptic ulcers. Gastroenteritis is in most cases a self-limiting disease that only requires supportive treatment like oral rehydration therapy and bed rest. Antibiotics may be used in bacterial cases that are severe or not resolving spontaneously. Antidiarrheals may be used in some cases but should be avoided as far as possible. A suitable probiotic containing Lactobacillus casei and Saccharomyces boulardii may be commenced once vomiting subsides and after the infection resolves to restore the normal intestinal flora.
Stomach Acid Problems
The stomach maintains a constant supply of gastric acid which fluctuates with certain conditions like eating and at certain times of the day. This is controlled by a number of local and systemic factors, both neural and hormonal. Stimulation of gastric acid is regulated by vagus nerve, enteric nervous system and gastrin. It is inhibited by the hormone somastatin and other neural and hormonal factors as discussed under gastric acid secretion.
Excessive Stomach Acid Problem
Hyperchlorhydria is the term for excessive acidity of the stomach juices even though the quantity may be within the norm. It rarely causes any problems except when there are underlying disorders like GERD which then allows these highly acidic juices to enter the esophagus.
Zollinger-Ellison syndrome is a rare condition where there is an overproduction of stomach acid due to the formation of growths that secrete gastrin. Since gastrin is one of the main hormonal stimulating factors for stomach acid, the quantity of acid increases.
Diminished Stomach Acid Problem
Hypochlorhydria is the term for reduced stomach acid volume or less acidic stomach juices. Symptoms may depend on the severity of the condition. It is considered to be synonymous with achlorhydria below but may be seen as a state of low acid levels or reduced acidity before it reaches the full extent of achlorhydria.
Achlorhydria is a condition of very low stomach acid or reduced acidity as defined by :
- change in pH above 6.5 or pH > 5.09 (men) and >6.81 (women).
- maximal acid output (MAO) < 6.9 mmol/h (men) and 5 mmol/h (women).
- reduced conversion of pepsinogen into pepsin as this requires HCl.
Stomach Acid Problem Causes
The causes of excessive or diminished stomach acid varies but are largely due to factors such as :
- Hormone-secreting growths
- Other tumors and cancer
- H.pylori infection
- Age-related changes
Stomach Acid Problem Symptoms
Both excessive and diminished stomach acid may affect digestion to varying degrees. The symptoms may therefore differ and can include :
- Nausea and vomiting
- Abdominal pain
- Diminished appetite
- Nutrient deficiencies
- Small intestinal bacterial overgrowth (SIBO) with achlorhydria
Stomach Acid Problem Treatment
The treatment differs for excessive and diminished stomach acid.
Excessive stomach acid may require the use of acid suppressing drugs like proton inhibitors. In the case of Zollinger-Ellison syndrome, the tumor may have to be surgically removed. Underlying causes when identified also need to be treated.
Diminished stomach acid may require the use of certain drugs that increase acidity particularly during meal time like betaine HCl. Tumors also need to be removed surgically. Underlying causes like H.pylori infection need to be addressed with eradication therapy.
Stomach Ulcer Problem
The lining of the alimentary tract is able to withstand significant irritation and injury. It replicates rapidly thereby replenishing itself quickly in the event of any injury that compromises its structural integrity. However, with severe or prolonged irritation the lining may progress from mild irritation to major inflammation and even ulceration.
Stomach Ulcer Problem Definition
Stomach ulcers are open sores in the lining of the stomach. It usually extends to the superficial layers but can extend deeper or in rare cases through the entire stomach wall (perforations). Stomach ulcers are a complication of gastritis – inflammation of the stomach lining. It often involves the duodenum and esophagus and is jointly referred to as peptic ulcer disease.
Stomach Ulcer Problem Causes
A number of factors may irritate the stomach lining. Prolonged inflammation is more likely to progress to ulceration. Some of the causes include :
- H.pylori infection
- Excessive use of NSAIDs (non-steroidal anti-inflammatory drugs) and osteoporosis medication.
- Chronic alcohol abuse
It is more common in cigarette smokers and in a person undergoing prolonged psychological stress although these are risk factors and not the cause of ulcers.
Stomach Ulcer Problem Symptoms
Stomach ulcers can remain asymptomatic for long periods of time. It is marked by episodes of acute symptoms which may resolve when treated. However, the ulceration may persist.
- Burning stomach pain worse at night and when hungry.
- Vomiting in severe cases
- Bleeding ulcers which may present as dark blood in the vomit (hematemesis) or stools (melena)
- Changes in appetite
- Weight loss
Stomach Ulcer Problem Treatment
Acid suppressing drugs like proton pump inhibitors (PPIs) and H2 blockers are used along with agents to neutralize acids (antacids). Sometimes this is sufficient to allow the stomach ulcer to heal. H.pylori infection needs to be treated with antibiotics (eradication therapy). Drugs such as sucralfates may help to protect the destroyed portions of the stomach lining thereby allowing it to heal.
Stomach Emptying Problem
After undergoing digestion in the stomach, most of the solid food is converted into a fluid known as gastric chyme. The outflow of this chyme from the stomach into the duodenum is carefully regulated by the controlled action of the pylorus – pyloric pump.
Stomach Emptying Problem Definition
Gastroparesis is a delay in the emptying of gastric chyme from the stomach. It is also referred to as delayed gastric emptying. Normal gastric emptying is largely regulated by the vagus nerve and any dysfunction or damage to this nerve can lead to gastroparesis.
Stomach Emptying Problem Causes
The most common cause of gastroparesis is diabetes mellitus. In this case gastroparesis occurs with prolonged and poorly controlled diabetes mellitus. Other causes include:
- Viral infections
- Eating disorders like anorexia nervosa and bulimia
- Stomach surgery
- Neuromuscular diseases like scleroderma or Parkinson’s disease
- Endocrine disorders like hypothyroidism
Stomach Emptying Problem Symptoms
The symptoms of gastroparesis are largely similar to more common stomach problems like gastritis. This includes :
- Abdominal pain
- Weight loss
- Lack of appetite
- Abdominal distention
Stomach Emptying Problems Treatment
Gastroparesis is treated and managed by a combination of medication and dietary change. Drugs such as metoclopramide promote stomach emptying, antiemetic ease nausea and vomiting, and some drugs like erythromycin (antibiotic) increase stomach muscle contractions. In some patients who do not respond well to medication, a device known as a gastric neurostimulator is surgically implanted to promote gastric emptying.
An overgrowth of stomach tissue is known as a a mass or tumor. It can be either benign (non-cancerous) or malignant (cancerous).
Benign Stomach Growth
Benign growths are an overgrowth of cells which are the same as the tissue in which it originates. It is usually not abnormal in shape, size or other cellular characteristics. These growths can be classified as mucosal or non-mucosal tumors. Benign tumors that are isolated to the mucosa and extend from the stomach surface are known as stomach polyps. Some benign tumors have the potential to become cancerous and should be carefully monitored.
Malignant Stomach Growths
Stomach cancer (gastric carcinoma) is a growth of abnormal cells which somewhat resemble the tissue of origin. These malignant growths are highly invasive, multiplying rapidly and destroying neighbouring healthy tissue cells. It also has the potential to spread to surrounding organs and structures, or distant sites via the bloodstream or lymphatic system.
Stomach Growth Causes
The exact cause of both benign and malignant growths are not always known. Genetic factors play a strong role in both types of growths and this may be inherited. Other factors that can contribute to growths include :
- Cigarette smoking
- Overuse of proton pump inhibitors (PPIs)
- Certain types of foods (salted, pickled or smoked foods in particular)
- H.pylori infection
Stomach Growth Symptoms
Both benign and malignant growths may be asymptomatic particularly in the early stages. Symptoms are largely dependent on the size of the tumor and also the spread to other structures or organs with malignant tumors. Symptoms include :
- Abdominal pain
- Bleeding seen as hematemesis (dark blood in the vomit) and melena (black tarry stools).
- Abdominal mass
- Bloating after eating even small meals
- Weight loss
Stomach Growth Treatment
Surgery is the main treatment option for both benign and malignant tumors. Other therapeutic measures for stomach cancer may require the use of anti-cancer drugs (chemotherapy) and radiation therapy. Underlying stomach disorders need to be treated appropriately like antibiotics for H.pylori infection.