Remember to check allergy status


Adult Treatment - Gastro-Intestinal Tract Infections

Traveller's diarrhoea


Prophylaxis rarely, if ever, indicated.[1D] Consider stand-by antimicrobial only for patients at high risk of severe illness,[2D] or visiting high risk areas.[1D,2D]

Medicine Calendar

Standby: azithromycin

500mg OD

1-3 days

Prophylaxis/treatment: bismuth subsalicylate

2 tablets QDS

2 days

Clostridium difficile


Stop unnecessary antibiotics and/or PPIs and antiperistaltic agents1,2 B+
Mild cases (<4 episodes of diarrhoea per day) may respond without metronidazole. 70% respond to metronidazole in 5 days; 92% in 14 days3

If severe symptoms or signs (below) should treat with oral vancomycin, review progress closely and consider hospital referral.

Admit if severe: T >38.5; WCC >15, rising creatinine or signs/symptoms of severe colitis 1 C

Medicine Calendar

1st episode: metronidazole 1 A-

400mg TDS

10-14 days 1 C

Severe/type 027/recurrent: oral vancomycin 1 A-

125mg QDS

10-14 days then taper 1 C

OR Recurrent/2nd line: fidaxomicin

200mg BD

10 days1 C

Infectious diarrhoea

Antibiotic therapy not indicated unless systemically unwell. 2 C. If systemically unwell and Campylobacter spp suspected (e.g. undercooked meat and abdominal pain), consider clarithromycin for 5–7 days if treated early (within 3 days). 3 C

Medicine Calendar

If systematically unwell and Campylobacter spp suspected, consider clarithromycin if treated early (within 3 days).3 C


5–7 days



Treat all household contacts at the same time PLUS advise hygiene measures for 2 weeks (hand hygiene, pants at night, morning shower [include perianal area]) PLUS wash sleepwear, bed linen, dust, and vacuum on day one. 1 C
Child <6 mths add perianal wet wiping or washes 3 hourly during the day.

Medicine Calendar


100mg 1 C

stat dose but repeat after 2 weeks if infestation persists

Oral candidiasis

CKS- Oral Candida

Topical azoles are more effective than topical nystatin.

Oral candidiasis rare in immunocompetent adults; consider undiagnosed risk factors including HIV.

Fluconazole if extensive/severe candidiasis, or HIV or immunosuppression.

Medicine Calendar

miconazole oral gel 1,2,3,A-7

20mg/mL QDS (hold in mouth after food)

7 days or until 2 days after symptoms resolve 1A-

or nystatin suspension if miconazole not tolerated 1,2,4,5,7,A-

100,000 units QDS after meals

7 days or until 2 days after symptoms 7C

If extensive/severe candidiasis: fluconazole oral 4,5,6,7A-

50mg OD or 100mg OD (if HIV or immunocompromised)

7-14 days

Helicobacter pylori

NICE dyspepsia
NICE H. pylori
PHE H.pylori

Treat all positives 2 in known duodenal ulcer (DU), gastric ulcer (GU) 1A+ or low grade MALToma. 2B+ In Non-Ulcer dyspepsia NNT is 14 3A+,4B+

Do not offer eradication for GORD1C
Do not use clarithromycin, metronidazole or quinolone if used in past year for any infection5A+,6A+

Penicillin allergy:use proton pump inhibitor (PPI) plus clarithromycin & metronidazole; if previous clarithromycin use PPI + bismuth salt + metronidazole + tetracycline. In penicillin allergy and relapse see NICE

Relapse and previous metronidazole and clarithromycin use: use PPI PLUS amoxicillin, PLUS either tetracycline or levofloxacin1

Retest for H. pylori post DU/GU or relapse after second line therapy: using urea breath test or stool antigen test OR consider endoscopy for culture and susceptibility1C

Medicine Calendar

Always Use PPI1,8
First Line and Second Line1A+:

PPI TWICE DAILY WITH amoxicillin 1G BD PLUS either clarithromycin 500mg BD or metronidazole 400mg BD

All for 7 days1,9A, MALToma 1 C 14 days

Penicillin allergy:1,7

PPI TWICE DAILY PLUS bismuth subsalicylate 525mg QDS PLUS metronidazole 400mg BD PLUS tetracycline hydrochloride 500mg QDS

All for 7 days1,9A, MALToma 1 C 14 days

Relapse & previous metronidazole and clarithromycin use:

PPI TWICE DAILY PLUS Amoxicillin 1G BD PLUS tetracycline hydrochloride 500mg QDS OR levofloxacin 250mg BD

All for 7 days1,9A, MALToma 1 C 14 days

Third line on advice:

PPI TWICE DAILY PLUS bismuth salt PLUS two antibiotics not previously used, OR rifabutin 150mg BD, OR furazolidone 200mg BD

14 days

The POCAST project is funded by the National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Healthcare Associated Infections and Antimicrobial Resistance at Imperial College London and by the Imperial College Healthcare Charity (Grant Ref No:7006/P36U).