Antibiotics for Children With Severe Diarrhoea

Inclusion Criteria: * Children aged 2 - 23 months, presenting to a designated health care facility at a participating study site with * Diarrhoea per caregiver perception and at least 3 loose or watery stools in the previous 24 hours, * Diarrhoea for less than 14 days prior to screening and with at least one of the following criteria at presentation: * Signs of some or severe dehydration as per WHO Pocket Book 2013 * Moderately wasted as defined by a mid-upper arm circumference (MUAC) less than 125 mm (but greater than or equal to 115 mm) or a weight-for-length z-score (WLZ) greater than -3 standard deviations (SD) and less than or equal to -2 SD after rehydration during stabilization period or * Severely stunted (length-for-age z-score (LAZ) \<-3 SD) and * Parent or guardian (caregiver) willing to allow household visits on day 2 and day 3 and willing to return to facility on day 90 and * Parent or guardian (caregiver) provides a consent for trial participation on behalf of the child, based on local standards Exclusion Criteria: * Dysentery (gross blood in stool reported by caregiver or observed by healthcare worker (HCW)), * Suspected Vibrio cholerae infection (determined according to WHO guidelines or clinical suspicion), * Previously or currently enrolled in the ABCD study, * Concurrently enrolled in another interventional clinical trial, * Sibling or other child in the household enrolled in the ABCD study and currently taking study medication, * Signs of associated infections (pneumonia, severe febrile illness, meningitis, mastoiditis or acute ear infection) requiring antibiotic treatment, * Documented antibiotic use in the 14 days prior to screening (not including standard use of prophylactic antibiotics, i.e. co-trimoxazole use in human immunodeficiency virus (HIV) -exposed children), * Documented use of metronidazole within the last 14-days, * Known allergy or contraindication to azithromycin antibiotics, * Severe acute malnutrition (SAM) defined as weigh-for-length Z-score (WLZ) less than -3 SD, or MUAC less than 115 mm, or edema of both feet, or * Living too far from the enrolment health center to ensure adequate Directly Observed Therapy (DOT) on day 2 and day 3