Gastroenteritis

Question 1

Define gastroenteritis?

Answer 1

acute inflammation of lining of GI tract-> nausea, vomiting, diarrhoea, and abdominal discomfort

infectious colitis= swelling and irritation of colon

Question 2

outline the aetiology of gastroenteritis?

Answer 2

Caused by viruses, bacteria, protozoa or toxins contained in contaminated food or water (faecal-oral route)

Question 3

what are the risk factors for gastroenteritis?

Answer 3

exposure to contaminated food or water sources

close contact with infected people

poor hygiene

extreme ages

HIV infection

organ transplantation

chronic ilness

Question 4

what key questions should be asked for diagnosing gastroenteritis?

Answer 4

ASK ABOUT TRAVEL, PEOPLE AROUND HAVING SIM SYMP, SPEC TIME FROM STARTING

Question 5

give examples of viruses , bacteria and protoctists that cause gastroenteritis?

Answer 5

Question 6

which virus is likely to cause outbreaks of D + V in institutions with elderly?

Answer 6

norovirus

Question 7

what organism is likely to be the cause of a uni student having watery diarrohea?

Answer 7

campylobacter jejuni

Question 8

what organism is likely to cause rapid onset diarrhoea after a meal?

Answer 8

Staph Aureus ( toxins produced) 
Bacilus cereus

Question 9

which organism is likely to be cause of elderly on antibiotics with explosive diarrhoea?

Answer 9

pseudomembranous colitis: C difficile

Question 11

which organism is the cause of traveller’s diarrhoea?

Answer 11

E. coli

Question 12

what are tuberculosis and yernia associated with? and what can they mimic?

Answer 12

RIF pain and travel

both mimic ileo-caecal crohn’s

Question 13

which organisms cause bloody diarrhoea ( dysentry)

Answer 13

CHESS

Question 14

which organisms are associated with improperly cooked meats?

Answer 14

S.aureus, C. perfringens

Question 15

Which organisms are associated with old rice?

Answer 15

B cereus, S aureus

Question 16

which organisms are associated with milk and cheese?

Answer 16

Listeria and campylobacter

Question 17

which organisms are associated with canned foods?

Answer 17

botulinism

Question 18

summarise the epidemiology of gastroenteritis?

Answer 18

common

serious cause of morbidity in the developing world

Question 19

what are the possible complications of gastroenteritis?

Answer 19

Dehydration

Electrolyte imbalance

Prerenal failure (due to dehydration)

Secondary lactose intolerance (particularly in infants)

Sepsis and shock

Haemolytic uraemic syndrome (associated with toxins from E. coli O157)

Guillain-Barre Syndrome may occur weeks after recovery from Campylobacter gastroenteritis

NOTE: botulism can lead to respiratory muscle weakness or paralysis

Question 20

what are the presenting symptoms of infective colitis?

Answer 20

abdo discomfort

diarrhoea

N and V

bloody/purulent/mucoid stools

severe abdo cramping

fever

tenesemus

Question 21

what are the presenting symptoms of gastroenteritis?

Answer 21

Sudden onset nausea, vomiting, anorexia

Viral gastroenteritis presents more with upper GI symp like N+V rather than D

DIARRHOEA (bloody or watery)
Note – dysentery is any type of gastroenteritis which causes bloody diarrhoea

Abdominal pain or discomfort

Fever and malaise

Question 22

how is the onset of symptoms caused by toxins different to symptoms caused by bacterial/ viral/ protozoal infection?

Answer 22

Toxins = early (1-24 hours)

Bacterial/viral/protozoal = 12+ hours

Question 23

what are the signs of gastroenteritis on physical examination?

Answer 23

Diffuse abdominal tenderness

Abdominal distension

Bowel sounds are often INCREASED

In SEVERE gastroenteritis: pyrexia, dehydration, hypotension and peripheral shutdown

IMPORTANT: ANY DIARRHOEAL CONDITION CAN LEAD TO DEHYDRATION so assess and address the patient’s hydration status immediately

Question 24

what are the appopriate investigations for gastroenteritis?

Answer 24

Bloods: FBC, blood culture (identify bacteraemia), U&Es (dehydration)

C diff causes raised WCC

Stool MC&S: faecal microscopy and analysis for toxins (particularly for the toxin causing pseudomembranous colitis (C. difficile toxin))

AXR or ultrasound: exclude other causes of abdominal pain (e.g. bowel perforation)

Sigmoidoscopy: usually unnecessary unless inflammatory bowel disease needs to be excluded

Question 25

what is the treatment for c difficile

Answer 25

Isolate

Oral metronidazole 10-14 days

• cause a disulfiram-like reaction (nausea, vomiting, flushing, discomfort, hangover-like symptoms) to alcohol so avoid alcohol during treatment

If refractory: vancomycin

Question 26

generate a mangement plan for gastroenteritis?

Answer 26

Bed rest – should stay at home until D+V cleared for 48h

Fluid and electrolyte replacement with oral rehydration solution (contains glucose and salt)

IV rehydration may be necessary in those with severe vomiting/ pts with signs of hypovolaemia (e.g. Tachy, low BP)

Most infections are self-limiting (so will go away with time)

Antibiotic treatment (ciprofloxacin or azithromycin) is only used if severe or immunocompromised or if infective agent has been identified by a stool culture

Question 27

if botulinim toxin is present due to clostridium botilinum, what is the treatment?

Answer 27

treat with botulinum antitoxin (IM) and manage in ITU

Question 28

what is the prognosis for gastroenteritis?

Answer 28

good prognosis-> most cases are self limiting