Bacterial gastroenteritis

What is bacterial gastroenteritis

Bacterial gastroenteritis is basically an acute bacterial inflammation of the stomach and/or intestines, either by the bacteria itself or through the toxins the bacteria produces. It is also known as “food poisoning” due to the bacteria in the food.

The bacteria that are mostly responsible for bacterial gastroenteritis are:

• Campylobacter jejuni
• Clostridium
• E. coli
• Salmonella
• Shigella
• Staphylococcus
• Yersinia

There can sometimes be outbreaks of various bacterial gastroenteritis infections among many people at a specific gathering, restaurant or party, who have eaten the same food and will all experience the same food poisoning symptoms.

If the food poisoning is due to a restaurant meal and has affected many people, the health authorities will usually investigate this quite thoroughly for the food preparation standards.

Bacterial gastroenteritis can also occur in areas with poor sanitation, in water that is infected with bacteria and this is often the case in developing countries.

Facts about bacterial gastroenteritis

• Bacterial gastroenteritis, is also know as “gastro” or a “stomach bug”
• Bacterial gastroenteritis is a common ailment in both adults and children
• About 10-20% of all gastroenteritis cases are due to a bacterial infection (the majority are due to a viral infection)
• Botulism is a very severe type of bacterial gastroenteritis (food poisoning) which can be fatal and is usually caused by using improper bottling or canning methods
• Treating drinking water by using certain (anti-bacterial) chemicals or boiling it kills most of the harmful bacteria that may be in contaminated water
• Good hygiene and sanitation can prevent most cases of bacterial gastroenteritis
• Reheating food too many times can cause bacterial gastroenteritis
• When in doubt about whether a food is safe to eat or not, throw it out
• It is not advisable to eat food prepared in areas of poor sanitation
• Statistics show that about 1 in 1000 people develop bacteria gastroenteritis every year

Symptoms of bacterial gastroenteritis

Symptoms can be mild to severe, depending on the severity of the bacterial gastroenteritis.

General symptoms of bacterial gastroenteritis are:

• Diarrhoea (this is the most common symptom to all the bacteria)
• Loss of appetite
• Nausea
• Stomach cramps
• Vomiting

If the person experiences severe diarrhoea and if it is also associated with vomiting, this can lead to severe dehydration, which requires immediate medical attention.

Young children and babies can experience dehydration from severe diarrhoea / vomiting much more quickly than adults so they need immediate medical attention to prevent complications.

Anyone experiencing diarrhoea for an extended period of time due to bacterial gastroenteritis should consult their doctor to get a suitable replacement for the electrolytes (salts and minerals) and fluids they have lost due to the diarrhoea and/or vomiting.

Causes of bacterial gastroenteritis

Bacterial gastroenteritis is caused by bacteria. Each type of bacteria causes slightly different symptoms, but all will invariably cause at the least, diarrhoea (mild to severe).

There are many types of bacteria that can produce symptoms associated with this condition, some of the most common bacteria are listed below:

• Campylobacter jejuni
• Clostridium
• E. Coli
• Salmonella
• Shigella
• Staphylococcus
• Yersinia

Main ways of infection

The main ways that a person can be infected by the bacteria is through the following:

• Food that has not been cooked, stored, handled or prepared properly
• Reheating meat dishes several times
• Unpasteurised dairy products (although this does not mean all unpasteurised dairy products will cause this condition, but some may)
• Drinking contaminated water
• Infection from a person with the bacterial infection

Some sources of the infection are improperly prepared food, reheated meat dishes, seafood, dairy, and bakery products. Each organism causes slightly different symptoms but all result in a bacterial gastroenteritis infection

Prevention of bacterial gastroenteritis

Non-preventable risk factors

There are some ways that bacterial gastroenteritis may be difficult to prevent from occurring:

• Incorrect bottling/canning – people who make jams or other bottled food products need to use correct and hygienic bottling/canning methods, otherwise the food can become infected with bacteria and cause bacterial gastroenteritis and even botulism in very severe cases
• Infected person – it is very easy to be infected by a person with existing bacterial gastroenteritis if you are in close proximity to them (family member, work colleague, close friends). It is advisable that people with bacterial gastroenteritis stay away from work / school until the infectious timeframe has passed

Preventable risk factors

Bacterial gastroenteritis can be prevented through the following :

• Boiling contaminated water – drinking contaminated water (with bacteria) will cause bacterial gastroenteritis. Treating drinking water by using chemicals or boiling it kills most of the harmful bacteria that may be in contaminated water
• Poor food hygiene – preparing food in an unhygienic manner can lead to bacterial contamination and bacterial gastroenteritis, especially if raw food is being handle (such as chicken or pork) and hands/equipment are not washed in between handling different types of food
• Proper food handling – storing, preparing and handling food needs to be done in a hygienic way to avoid bacterial infection. People who are handling food must wash their hands thoroughly with soap and warm water for about 10 to 20 seconds to reduce the risk of catching and spreading harmful bacteria
• Reheating meat too many times – meat should only be re-heated once (maybe twice if it has been stored in the refrigerator properly the first use) and not more than this, because it provides opportunity for bacteria to proliferate and cause bacterial gastroenteritis when it is consumed
• Using unpasteurised dairy products – there is some controversy about whether or not unpasteurised dairy products can cause bacterial gastroenteritis. Cold pressed unpasteurised milk removes bacteria and keeps the goodness intact

Complications of bacterial gastroenteritis

There are some complications of bacterial gastroenteritis for both adults and children:

• Dehydration – this can quickly become very serious in babies and children due to the loss of electrolytes through excessive vomiting and diarrhoea. Any baby or child who is vomiting or has severe diarrhoea needs medical attention to rehydrate their body with electrolytes and fluids to prevent any complications from dehydration

Other, very serious complications of bacterial gastroenteritis are:

• Botulism – this is a very serious complication which is due to incorrect bottling/canning of foods, such as jams, preserves and bottled foods. It can occur due to incorrect methods either at home or from foods purchased from the shops

When to see a doctor about bacterial gastroenteritis

People who have any of the symptoms associated with bacterial gastroenteritis need to see their doctor to have it diagnosed and treated, especially babies and young children who can be at greater risk of dehydration and associated complications.

If several people contract bacterial gastroenteritis and food preparation has been suspected the relevant authorities will need to be informed, to test the food preparation practices of the place where the food was purchased.

Diagnosis of bacterial gastroenteritis

Initial diagnosis of bacterial gastroenteritis includes the following tests:

• Medical history – the doctor will ask a series of question about the onset (start) of symptoms, how severe the symptoms are and the duration of symptoms
• Physical examination – the doctor will perform a general physical examination to determine if there are any obvious symptoms of bacterial gastroenteritis, such as pain in the abdomen

Diagnostic tests

If bacterial gastroenteritis is suspected, then the following diagnostic tests may also be requested to confirm (or rule out) diagnosis:

• Blood test – a blood test may be requested to determine if it shows an elevation of the white blood cells (which indicates infection)
• Urine test – a urine test can be requested to rule out any other gastrointestinal infection (bladder infection, urinary tract infection) which may present with similar symptoms
• Stool culture – a sample of the faeces can be taken to examine it for the type of bacteria present and which has caused the bacterial gastroenteritis
• Examination of the suspected food – if it is viable to do so, the food causing the symptoms may be taken away to be tested for the specific bacteria (especially if it has affected many people)

Conventional treatment of bacterial gastroenteritis

Conventional treatment of bacterial gastroenteritis consists of the following.

Medication

This is the main way to reverse any potential adverse health symptoms of bacterial gastroenteritis:

• Antibiotics – the doctor will prescribe antibiotics to reduce the bacterial population in the gastrointestinal system, reduce symptoms and reduce disease length. Antibiotics will only work on a bacterial infection (not viral), so if viral gastroenteritis is suspected, they will not likely be prescribed
• Anti-diarrhoea medication – depending on the severity of the diarrhoea symptoms, the doctor provide this medication intravenously or a prescription for tablets
• Anti-nausea medication – depending on the severity of any nausea symptoms, the doctor may provide this medication intravenously or a prescription for tablets
• Electrolyte rebalancing powder – this powder is purchased over-the-counter at the pharmacy and is mixed with water. It contains the right balance of salts, sugars and minerals to help the body recover the electrolytes lost after vomiting and/or diarrhoea

Dietary and lifestyle modifications

In addition to the medications (mainly the electrolytes, but also the other medications if symptoms are bad enough), the doctor will also recommend the following:

• Fluids – plenty of water should be given, in small amounts and at regular intervals and juice which has been diluted with water: the ratio should be 1/2 juice and 1/2 water
• Rest – plenty of bed rest will be recommended to help the body heal itself from the bacterial infection
• Soft foods – it will be recommended to eat foods that are soft and easily digested to reduce pressure on the digestive system (which needs to digest and absorb foods) in order to enable the digestive system time to recover from the bacterial gastroenteritis. The doctor will recommend soft foods, such as ripe bananas, rice and bread for a few days

Alternative / complementary treatment of bacterial gastroenteritis

The alternative / complementary treatment for bacterial gastroenteritis is basically the same as for conventional (without the medications), together with some other additions.

Herbs

There are no herbs which are useful for treating bacterial gastroenteritis.

Vitamins

There is a few vitamins which are recommended to support the immune system while the body is recovering from bacterial gastroenteritis:

• Vitamin A – the antioxidant vitamin A is an excellent booster for the immune system, to help it fight off bacterial infection
• Vitamin C – the antioxidant vitamin C, together with the bioflavonoids, provide an excellent boost for the immune system, to help it fight off bacterial infection
• Vitamin E – the antioxidant vitamin A is an excellent booster for the immune system, to help it fight off bacterial infection

Minerals

There are no minerals which are recommended for treating bacterial gastroenteritis. While the electrolytes (chloride, potassium and sodium) and glucose are needed to help with loss of fluids, they need to be in specific amounts and it is not possible or feasible to make your own in the correct dosage, so it is advisable to buy an electrolyte formula from a chemist to replenish and replace electrolytes and glucose.

Other nutrients

There is one main vitamin which is useful for treating bacterial gastroenteritis:

• Probiotics – the “good” bacteria in probiotics will help to re-populate the gastrointestinal system to reduce the proliferation of the “bad” bacteria causing the bacterial gastroenteritis. In addition to this, the live cultures in the probiotics are very beneficial in gastrointestinal health overall

Dietary modifications

There are some useful dietary modifications to help avoid bacterial gastroenteritis or reduce worsening of symptoms:

• Drink more fluids – plenty of water should be given, in small amounts and at regular intervals and juice which has been diluted with water: the ratio should be 1/2 juice and 1/2 water
• Eat easy to digest foods – for about 3-5 days after a bacterial gastroenteritis infection, it is recommended to eat soft foods, which are easier to digest and allow the gastrointestinal system an opportunity to recover from the bacterial infection without having to work hard to digest and absorb foods like meat. The best foods to eat are well cooked rice, toast and vegetable soup
• Eat vegetables and fruit – both vegetables and fruit provide a high level of nutrients, such as vitamins, minerals and antioxidants and are very easy for the body to digest. Just ensure you eat softer and less acidic fruits (such as bananas) as they put less pressure on the digestive system

Lifestyle modifications

There are one lifestyle modifications which are useful for helping with healing from bacterial gastroenteritis:

• Rest – plenty of bed rest will be recommended to help the body heal itself from the bacterial infection. Try to stay in bed or at least avoid doing anything strenuous for a few days, to give the body a chance to heal itself. Children should be kept at home from school for the duration that the doctor recommends, to help them heal from the infection and to prevent infecting other children

Alternative treatments

There are no other alternative treatments which are useful for treating bacterial gastroenteritis.

Always ensure that you notify your medical practitioner of any supplements that you want to take – it may interfere with other medication or conditions you have. Confirm with your doctor it is safe to take before you try it.

Living with bacterial gastroenteritis

People who are living with bacterial gastroenteritis, can help improve their condition with the following strategies:

• Avoid alcohol – the gastrointestinal system is not functioning well and alcohol will only make symptoms worse, so avoid it
• Drink more fluids – plenty of water should be given, in small amounts and at regular intervals and juice which has been diluted with water: the ratio should be 1/2 juice and 1/2 water
• Eat easy to digest foods – for about 3-5 days after a bacterial gastroenteritis infection, it is recommended to eat soft foods, which are easier to digest and allow the gastrointestinal system an opportunity to recover from the bacterial infection without having to work hard to digest and absorb foods like meat. The best foods to eat are well cooked rice, toast and vegetable soup
• Eat vegetables and fruit – both vegetables and fruit provide a high level of nutrients, such as vitamins, minerals and antioxidants and are very easy for the body to digest. Just ensure you eat softer and less acidic fruits (such as bananas) as they put less pressure on the digestive system
• Rest – plenty of bed rest will be recommended to help the body heal itself from the bacterial infection. Try to stay in bed or at least avoid doing anything strenuous for a few days, to give the body a chance to heal itself. Children should be kept at home from school for the duration that the doctor recommends, to help them heal from the infection and to prevent infecting other children

Caring for someone with bacterial gastroenteritis

Partner

If your partner has bacterial gastroenteritis, you may be able to help them through the following strategies:

• Allow your partner to rest – your partner needs bed rest to help their body recover and heal from the bacterial gastroenteritis, so allow them to sleep and rest until they feel better
• Provide fluids and food – your partner needs to ensure they have adequate fluids and soft foods to eat, but they may be too sick to prepare the foods for themself, so it would be beneficial if you could prepare some soup, toast, cook some rice (and maybe add some honey) and give them fluids at regular intervals

Friends

If your friend has bacterial gastroenteritis, you may be able to help them through the following strategies:

• Allow your friend to rest – your friend needs bed rest to help their body recover and heal from the bacterial gastroenteritis, so allow them to sleep and rest until they feel better

Parents

If your child has bacterial gastroenteritis, you may be able to help them through the following strategies:

• Allow your child to rest – your child needs bed rest to help their body recover and heal from the bacterial gastroenteritis, so allow them to sleep and rest until they feel better
• Inform the school – if your child has bacterial gastroenteritis, you will need to inform the school in case the food they have eaten was also eaten by other children in case they become sick too
• Keep your child home – a child that is sick with bacterial gastroenteritis needs to be kept away from school to avoid infecting other children with the bacteria
• Medication – if the doctor has provided medication (for nausea or diarrhea) for your child, ensure they take it as directed
• Provide fluids and food – your child needs to ensure they have adequate fluids and soft foods to eat, so it would be beneficial if you could prepare some soup, toast, cook some rice (and maybe add some honey) and give them fluids at regular intervals to prevent dehydration

References

Last reviewed and updated: 14 May 2024