Introduction
Inflammation in the stomach or small intestine leads to diarrhea due to increased bowel movement. It may or may not be associated with abdominal pain, fever, and vomiting. Increased bowel frequency is defined as three or more loose, watery stools in 24 hours or at least 200 grams of feces per day. Bacterial gastroenteritis can be bacterial, viral, fungal, and parasitic. The symptoms include diarrhea, vomiting, nausea, and abdominal pain. The cases of bacterial gastroenteritis are generally self-limiting, which means it can stop itself. However, some supportive management and antibiotic therapy can cure the disease.
What Are the Causes of Bacterial Gastroenteritis?
The cause of gastroenteritis can be bacterial, viral, fungal, or parasitic. However, this article is about the bacterial cause of gastroenteritis. The most common causative agents are adenovirus, rotavirus, and norovirus. Besides these viruses, bacterias causing gastroenteritis are enterotoxigenic Escherichia coli (ETEC) and Clostridium perfringens. Bacteria are responsible for more severe cases of gastroenteritis than other pathogens. Some other bacteria causing the infection are Campylobacter and nontyphoidal Salmonella.
What Is the Epidemiology of Bacterial Gastroenteritis?
Bacterial gastroenteritis is one of the most common diseases around the world. It is associated with almost 1.5 to 2.5 million death cases per year. One of the most common diseases affecting children below five years, approximately more than four billion children are affected by the disease every year.
What Is the Classification of Bacterial Gastroenteritis?
Depending on the duration of symptoms, gastroenteritis can be classified into the following categories:
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Acute Gastroenteritis: 14 days or less than the duration of symptoms.
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Persistent Gastroenteritis: Symptoms visible for more than 14 days but not exceeding 30 days.
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Chronic Gastroenteritis: Duration of symptoms lasts for more than 30 days.
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Recurrent Gastroenteritis: Recurrence of diarrhea after every seven days of no signs.
What Are the Symptoms of Bacterial Gastroenteritis?
The signs presented by patients of bacterial gastroenteritis are:
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Diarrhea: Watery or loose stool with or without the presence of bloodstains.
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Nausea: The feeling of vomiting and stomach discomfort.
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Vomiting: Forceful throwing up of the contents of the stomach.
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Abdominal pain.
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Fever: Increased body temperature, suggesting an aggressive organism as the causative agent.
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Dehydration due to excessive diarrhea.
In severe cases, the following symptoms are observed:
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Dry Mucous Membranes: Xerostomia or dry mouth can occur due to excess water loss from the body (dehydration).
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Decrease in Elasticity of the Skin: It does not easily come to its original shape if the skin is stretched and pulled.
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Tachycardia: Increase in heart rate with almost 100 beats per minute.
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Bloody Stools: Inflammation of the stomach lining and intestine can cause ulcers due to mucosal abrasion of the gut wall.
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Hypotension: Decreased blood pressure.
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Orthostasis: A normal physiological reaction of the sympathetic system to overcome a fall in blood pressure when a person was lying down and assumed back to an upright position.
How to Evaluate Bacterial Gastroenteritis?
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Thorough medical history and physical examination are the first steps in evaluating the disease. Physical examination presents tenderness in the abdomen.
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A serum electrolyte panel is indicated to check for abnormal electrolyte levels in severe fluid volume loss cases.
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With the help of blood tests, though a complete blood test cannot help differentiate between bacterial causes and other causes, it can help evaluate the severity and other complications. Such as, in cases of bacterial invasion and pseudomembranous colitis, there is an increase in white blood cell count.
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Blood testing is advised to diagnose bacterial pathogens in cases with excessive dehydration and volume loss, severe abdominal pain, pregnancy, elder individuals above 70 years of age, and immunocompromised patients. A stool culture can help identify three common bacteria - Campylobacter, Shigella, and Salmonella.
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In cases of bloody diarrhea, additional testing for Shiga toxin and leukocytes in feces is done to look for enterotoxigenic Escherichia Coli (ETEC).
What Is the Treatment of Bacterial Gastroenteritis?
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Antibiotic Therapy: In bacterial gastroenteritis, especially in Shiga toxin-producing E.coli, antibiotics should be advised. Azithromycin or Fluoroquinolones can be advised in severe cases like greater than six to seven stools in a day and fever, cases of elderly people (above 70 years), and mucus or blood in the stool. In pregnant women, the drug of choice is Ampicillin. It is also stated by the recent guidelines of the centers for disease control and prevention that oral Vancomycin or Fidaxomicin should be advised in nonsevere cases and Metronidazole for severe cases of bacterial gastroenteritis.
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Supportive Management: It includes rehydration in cases of dehydration. The preferable route is oral administration. If there are difficulties in oral rehydration, the intravenous route is used. The fluid intake should be slow, and in small amounts, as fast consumption can worsen nausea. Easy-to-digest food like bananas, rice, toast, and chicken should be started. Consumption of caffeine and alcohol should be avoided.
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Symptomatic Therapy: Loperamide is advised in cases of afebrile and non-bloody diarrhea.
Which Diseases Are Similar to Bacterial Gastroenteritis?
The most similar diseases to bacterial gastroenteritis are viral or fungal manifestations of gastroenteritis.
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Crohn’s Disease: This is a non-curing inflammatory disease of the bowel causing severe diarrhea, weight loss, abdominal pain, fatigue, and malnutrition.
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Microscopic Colitis: Inflammation of the large intestine (colon) causes persistent watery and loose diarrhea. As the name suggests, the disease is diagnosed only after a microscopic view of the colon.
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Lactose Intolerance: Difficulty digesting lactose (sugar) in the milk can cause issues such as gas, diarrhea, and bloating after consuming dairy products.
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Pseudomembranous Colitis: Clostridium difficile causes swelling and inflammation of the colon (large intestine). This infection is common after antibiotic usage and causes diarrhea.
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Irritable Bowel Syndrome: A common chronic disorder of the large intestine is showing symptoms such as abdominal pain, cramping, bloating, diarrhea, constipation, or both of these.
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Celiac Disease: Also known as gluten-sensitive enteropathy or celiac sprue. It is an immune reaction of the body towards gluten found in barley, wheat, and rye. The classic symptom of the disease is diarrhea, followed by fatigue, bloating, and anemia (low blood count).
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Malabsorption Syndrome: Disorders of the small intestine in which the intestine is not capable of absorbing enough nutrients leading to diarrhea, weight loss, and effects on other organs such as the brain, bones, liver, and nervous system.
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Acute HIV Infection: HIV is characterized by suppressing the body's immune system, thus increasing the chances of gastrointestinal infections and inflammations. The most common infections could cause diarrhea, abdominal pain, and digestive issues.
What Are the Complications of Bacterial Gastroenteritis?
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Dehydration and electrolyte depletion are the common complications seen in almost all cases.
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Transformation of acute gastroenteritis into chronic diarrhea leads to lactose intolerance or bacterial overgrowth in the small intestine.
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Enteric Fever: Also known as typhoid fever, is an infection caused by Salmonella typhi.
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Septicemia: Infection of blood by bacteria is known as septicemia or sepsis. It is one of the most extreme responses of the body to an infection. According to the organism involved, the death rate in cases of septic shock is as high as 50 %.
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Guillain-Barre Syndrome: A rare disorder where the body's immune system attacks its nerves. The symptoms start with tingling and weakness in the upper and lower limbs leading to paralysis of the whole body.
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Reactive Arthritis: Swelling and joint pain triggered by an infection in other parts of the body such as the intestines, urinary tract, or genitals. In cases of gastroenteritis by Salmonella, Campylobacter, or Yersinia, there are chances of reactive arthritis.
Conclusion:
Bacterial gastroenteritis is bowel inflammation that causes diarrhea due to increased bowel movements. The infection can be viral, fungal, or parasitic as well. Other symptoms include fever, abdominal pain, and vomiting. There can be dehydration due to excessive fluid loss from the body in some cases. In these cases, the administration of fluids either orally or intravenously is done. The treatment starts with antibiotic therapy, followed by supportive therapy.