For people presenting with diarrhoea during, or up to 8 weeks after, a course of antibiotic treatment:

• Assess the severity of the symptoms and consider whether hospital admission is appropriate.
• For further information on assessing symptoms (including the risk of dehydration) and when to admit, see the sections on hospital admission for children and adults in the CKS topic on Gastroenteritis.
• Exclude other potential causes of diarrhoea or contributing factors.
• Ask about recent contact with anyone with acute diarrhoea and/or vomiting, exposure to a known source of enteric infection (possibly contaminated water or food), and recent travel abroad.
• Check for drugs (other than antibiotics) known to cause diarrhoea (for example proton pump inhibitors — also a risk factor for Clostridium difficile infection) or exacerbate diarrhoea (for example laxatives).
• Check which antibiotics were prescribed and the duration of treatment.
• C. difficile infection is more common with certain antibiotics (see Risk factors).
• Consider the possibility of C. difficile infection.
• There are no clinical symptoms that are specific for C. difficile infection.
• However, suspect the possibility of C. difficile infection (particularly if the person is elderly) if risk factors are present.
• For information of assessing the severity of C. difficile infection, see Additional information.
• Check for any history of C. difficile infection — as the rate of recurrence is high.
• Send a stool sample to test for C. difficile toxin (for further information, see Testing).
• Check whether other cases of C. difficile infection have been reported recently — for example, within the care home or in the hospital ward from which the individual has been recently discharged. C. difficile-associated disease can occur in outbreaks.