Diarrhoea

Question 1

What is diarrhoea?

Answer 1

•From a clinical perspective, diarrhoea can be defined as the passage of:
Three or more loose or liquid stools per 24 hours, and/or
Stools that are more frequent than what is normal for the individual lasting <14 days, and/or
Stool weight greater than 200 g/day.

Question 2

How is diarrhoea classified based on duration?

Answer 2

•Based on duration, diarrhoea is classified as:
Acute (≤14 days)
Persistent (>14 days), or
Chronic (>4 weeks).

Question 3

Pathophysiology of diarrhoea

Answer 3

Diarrhoea occurs when various factors interfere with the normal process of digestion, resulting in decreased absorption or increased secretion of fluid and electrolytes, or increase in bowel motility.

Question 4

What are the two types of diarrhoea based on cause?

Answer 4

Infectious diarrhoea

Non-infectious diarrhoea

Question 5

How is infectious diarrhoea acquired?

Answer 5

Most are acquired through the faecal-oral route, from contaminated water or food. Most infections are self-limiting or treated easily.

Question 6

When are specific investigations warranted when a patient is diagnosed with infectious diarrhoea?

Answer 6

Specific investigations are warranted when resources are available in moderate to severe disease, or if there is a public health risk such as high risk for spreading disease to others.

Question 7

What are the bacterial infections that can cause infectious diarrhoea?

Answer 7

E.coli 
Campylobacter
Salmonella 
Shigella 
C. difficile 
S. aureus

Question 8

How is E.coli acquired?

Answer 8

(beef, pork, apple cider, milk, cheese and spinach)- common cause of traveller’s diarrhoea.

Question 9

How is campylobacter acquired?

Answer 9

• infection is generally acquired from undercooked contaminated poultry in developed countries.

Question 10

Clinical features of infectious diarrhoea when it is caused by campylobacter

Answer 10

Diarrhoea can be watery or bloody and is frequently associated with crampy abdominal pain.

Question 11

What are the serious complications of infection with campylobacter?

Answer 11

It has been linked to serious complications such as reactive arthritis and Guillain-Barre syndrome.

Question 12

How is salmonella acquired?

Answer 12

Poultry and eggs

Question 13

How is shingles acquired?

Answer 13

Common in day care centres. Presents with bloody stools, fever, abdominal cramps, and tenesmus.

Question 14

How is c.dif acquired?

Answer 14

This is one of the most common hospital-acquired (nosocomial) infections and is a frequent cause of morbidity and mortality among older hospitalised patients. C difficile colonises the human intestinal tract and after the normal microbiota has been altered by antibiotic therapy it can lead to pseudomembranous colitis. Recurrent disease is common and thought to be due to altered host immunity. C difficile produces toxins, which are implicated in the disease.

Question 15

How is s.aureus acquired?

Answer 15

Leads to vomiting, and in some instances diarrhoea, within 4 to 8 hours following the ingestion of food contaminated with pre-formed toxin.

Question 16

Which viral infections cause diarrhoea?

Answer 16

Rotavirus

Norovirus

Question 17

Clinical features of rotavirus

Answer 17

The leading cause of viral gastroenteritis and diarrhoeal deaths worldwide. It is a vaccine-preventable disease. It causes diarrhoea that results in volume depletion in children and young adults. This infection peaks during cooler weather.

Question 18

Clinical features of norovirus

Answer 18

this is a major cause in epidemic viral gastroenteritis. Noroviruses are the most common cause of outbreaks of non-bacterial gastroenteritis in the US.

Question 19

What are the causes of non-infectious of diarrhoea?

Answer 19

Medications
IBD
Bowel ischaemia 
IBS 
Radiation injury

Question 20

Which medications cause non-infectious diarrhoea?

Answer 20

A number of medications are associated with acute diarrhoea. These include, but are not limited to, antacids containing magnesium; antiarrhythmics (quinidine); antibiotics (as a primary cause or by causing C difficile infection); antihypertensives (beta-blockers, hydrochlorothiazide); anti-inflammatories (non-steroidal anti-inflammatory drugs, gold salts); antineoplastic agents; antiretroviral agents; acid-reducing agents (histamine H2-receptor antagonists, proton pump inhibitors); colchicine; prostaglandin analogues (misoprostol); theophylline; vitamins and mineral supplements; herbal products; heavy metals; and overuse of anticonstipation medications.

Question 21

Complications of diarrhoea

Answer 21

• Volume depletion and electrolyte disturbances
• Colonic perforation
• Toxic megacolon
• Intestinal obstruction and complications
• Complications in other organs, bacteraemia, and sepsis.
• Neurological problems
• Reactive arthritis
• Haemolytic uraemia syndrome (HUS) and thrombotic thrombocytopenia purpura (TTP)
• Hepatic necrosis
• Infection in pregnancy
• Impaired growth and development
• Gangrenous bowel

Question 22

Clinical features of volume depletion and electrolyte disturbances

Answer 22

Children and older adults are at high risk.
• With children, the carer may not be replacing the fluid loss in a timely manner.
• Volume depletion manifests with increased thirst, decreased urinary output with dark urine, inability to sweat, and orthostatic symptoms. In severe cases, it may lead to acute renal failure and mental status changes (confusion and drowsiness).

Question 23

How do you correct volume depletion and electrolyte disturbances?

Answer 23

Prompt correction of hydration is required using low-osmolarity oral rehydration solution and intravenous fluid if oral or nasogastric intake is impaired. In children, zinc supplementation is recommended as an adjunct to oral rehydration.

Question 24

Clinical features of colonic perforation

Answer 24

• This occurs principally in infants or severely malnourished patients and can be seen with Clostridium difficile, Salmonella, and Shigella infections.

Question 25

Treatment of colonic perforation

Answer 25

Urgent surgery is the treatment of choice.

Question 26

Clinical features of toxic megacolon

Answer 26

Broad-spectrum antibiotic use may lead to C difficile infection with the associated complications of toxic megacolon, sepsis, perforation, and death. Toxic megacolon can also be seen with Shigella, cytomegalovirus (CMV), or Yersinia infection, and in ulcerative colitis and Crohn's disease.

Question 27

Clinical features of intestinal obstruction and complications

Answer 27

This can occur in Shigella infections, helminth infections, and opportunistic infections in patients with AIDS. Crohn’s disease can also present with acute intestinal obstruction, intestinal perforation, peritonitis, and intra-abdominal abscess formation. The presenting symptoms are of crampy abdominal pain, nausea, vomiting, and abdominal distension.

Question 28

Treatment of intestinal obstruction and its complications

Answer 28

Treatment consists of nasogastric suction, strict nothing by mouth, and intravenous fluids. Antiparasitics and antibiotics may be needed, and surgery is considered if medical management fails.

Question 29

Clinical features of complications in other organs, bacteraemia, and sepsis

Answer 29

This can occur in severe infection. The normal microbiota may translocate across an inflamed colonic epithelium into the bloodstream. Endocarditis and osteomyelitis may complicate Salmonella infection. Myocarditis, glomerulonephritis, liver failure, peritonitis, and suppurative appendicitis may complicate Yersinia infection. •Yersinia infection may also be mistaken for acute appendicitis. C difficile infection may lead to profound bowel necrosis, multiple organ failure, and death.

Question 30

Treatment of complications in other organs, bacteraemia, and sepsis

Answer 30

* Antibiotic treatment and supportive care is indicated in cases of severe infectious diarrhoea especially when additional complications arise. Specifically, colon resection is sometimes necessary in severe C difficile-induced bowel necrosis. * It is important to consider the possibility of sepsis in any patient with acute diarrhoea

Question 31

Clinical features of neurological problems associated with diarrhoea

Answer 31

* Seizure is the most common neurological complication. It is a well-recognised complication of Shigella infection. Encephalopathy with lethargy, confusion, and headache can be seen. * Obtundation or coma and abnormal neurological signs, including posturing, are rare. In cases of fatal encephalopathy, cerebral oedema has been found at autopsy. Delirium and coma may be present in Salmonella infection. * Guillain-Barre syndrome may be seen as a late complication in Campylobacter enteritis. Listeria infection can cause meningitis.

Question 32

Clinical features of reactive arthritis

Answer 32

* This may be seen alone or in association with conjunctivitis and urethritis, a triad formerly known as Reiter's syndrome. * It may be seen in Shigella, Salmonella, Campylobacter, and Yersinia infections. The arthritis is a sterile inflammatory arthritis. Treatment is usually supportive with non-steroidal anti-inflammatory drugs.

Question 33

Clinical features of HUS and TTP

Answer 33

* HUS presents with haemolysis and acute renal failure, while TTP presents with fever, haemolytic anaemia, thrombocytopenia, renal failure, and neurological changes. * They can occur in infections with enterohaemorrhagic E coli and, less commonly, Shigella, particularly in young children and older adults who are exposed to antibiotics and antidiarrhoeal agents. * Rare cases of HUS with Campylobacter and Aeromonas have also been reported.

Question 34

Treatment of HUS and TTP

Answer 34

Treatment is supportive, but plasma exchange and glucocorticoids could be considered. Antibiotics should be avoided in infections secondary to enterohaemorrhagic E coli, as it is unclear if they increased risk of HUS.

Question 35

Clinical features of hepatic necrosis

Answer 35

This is rarely associated with Bacillus cereus infection

Question 36

Clinical features of infection in pregnancy

Answer 36

Listeria infection in pregnant women can lead to fetal death, premature birth, or infected newborns

Question 37

Clinical features of impaired growth and development

Answer 37

Enteroaggregative E coli, Cryptosporidium, Giardia, Entamoeba histolytica, helminths, and other enteropathogens have been implicated in impaired growth and development in infants and young children.

Question 38

Clinical features of gangrenous bowel

Answer 38

Ischaemic colitis may result in gangrenous bowel. The patient may develop severe volume depletion and shock and require surgical intervention.

Question 39

Common differentials of diarrhoea

Answer 39

* Rotavirus * Norovirus * Enteric adenovirus * Campylobacter * Shigella * Salmonella * E.coli * C.dif * Cholera * S.aureus * Bacillus cereus * Clostridium Perfringens * Listeria * Giardia * Entamoeba histolytica * Microsporidiosis * Medications * UC * Crohn’s disease * IBS

Question 40

Uncommon differentials of diarrhoea

Answer 40

* Bowel ischaemia * Radiation injury * Yersinia * Aeromonas * Cryptosporidium * Astrovirus * Plesiomonas * Klebsiella oxytoca

Question 41

What should a patient do to care for themselves if they have diarrhoea?

Answer 41

1) Drink oral rehydration salts 2) Avoid preparing food for other people 3) Wash hands carefully after going to the toilet. 4) Increase fluid intake.

Question 42

What do you examine in a patient with diarrhoea?

Answer 42

1) General condition 2) Temperature 3) Pulse and blood pressure 4) Hydration status 5) Weight 6) Abdominal examination

Question 43

How should a patient collect a stool sample?

Answer 43

* label a clean, screw-top container with your name, date of birth and the date * place something in the toilet to catch the poo, such as a potty or an empty plastic food container, or spread clean newspaper or plastic wrap over the rim of the toilet * make sure the poo doesn't touch the inside of the toilet * use the spoon or spatula that comes with the container to collect the poo, then screw the lid shut * if you've been given a container, aim to fill around a third of it – that's about the size of a walnut if you're using your own container * put anything you used to collect the poo in a plastic bag, tie it up and put it the bin * wash your hands thoroughly with soap and warm running water

Question 44

How should a patient store a stool sample?

Answer 44

1) Your sample of poo must be fresh – if it is not, the bacteria in it can multiply. This means the levels of bacteria in the stool sample won't be the same as the levels of bacteria in your digestive system. If the levels of bacteria don't match, the test results may not be accurate. 2) Your sample should be handed in as soon as possible, as sometimes it can't be analysed after being refrigerated – your doctor will tell you if this is the case. 3) If you can't hand your sample in immediately, find out how long it can be kept in the fridge. Your GP or the healthcare professional who requested the test will be able to tell you. If you can store it in the fridge, put the container in a sealed plastic bag first.

Question 45

What are stool samples used for?

Answer 45

1) Your GP or another healthcare professional may ask you for a stool sample to help them diagnose or rule out a particular health condition. 2) Poo contains bacteria and other substances that are in the digestive system. 3) By testing the levels of these substances and bacteria in your poo, it's possible to work out what's happening in your digestive system.

Question 46

How do practices reduce the risk of harm to patients and ensured?

Answer 46

* Robust systems to ensure each GP’s work is safely covered when not at their practice, such as ensuring that notes on the computer are clear and thorough enough for others to take over care and an on-call system where a GP covers any tasks which need to be actioned urgently. * Asking patients to ring in for results. This can help as the patient has responsibility for their results and takes an active role in their health. * The computer system can be set to flag up abnormal results needing action, and that these are seen by someone in the practice if requesting doctor is not in work that day. This might take the form of a ‘buddy system’ between GPs. * Discussion with a patient on when to seek help if symptoms do not resolve (safety netting). This enables a patient to know if they expect to recover on their own and when (and how) to seek help if symptoms worsen or don’t improve.