Gotuzzo 1989.

Methods	Randomized controlled trial Generation of allocation sequence: block randomization with a random number table Allocation concealment: unclear Blinding: nil Inclusion of all randomized participants: inadequate, 32% Duration: not reported
Participants	Number of participants enrolled: 174 Number of participants analysed: 55 Loss to follow up: 7 Inclusion criteria: adults; dysentery; duration of illness less than 24 hours; informed consent Exclusion criteria: antibiotic therapy within 48 hours
Interventions	(1) Cotrimoxazole (160/800 mg twice a day for 5 days) (2) Norfloxacin (800 mg single dose)
Outcomes	(1) Days to last unformed stool (2) Number of culture positive follow up
Notes	Location: Peru Setting: participants were not hospitalized but followed up in the out‐patients Follow‐up period: 2 weeks Antibiotic sensitivity pattern of Shigella isolates: 84% in the cotrimoxazole group and 86% in the norfloxacin group were sensitive to cotrimoxazole; 100% sensitivity in both groups to norfloxacin Funding source(s): in part by the International Collaboration in Infectious Disease Research grant 5 P01 A120130 from the National Institute of Allergy and Infectious Diseases
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	Block randomization with a random number table
Allocation concealment?	Unclear risk	Not mentioned
Blinding? All outcomes	High risk	Not mentioned but unlikely to be blinded as the dosage regimens of interventions were different
Incomplete outcome data addressed? All outcomes	High risk	174 entered the study; analysis was done on 55 (32%) patients; 62 had Shigella in culture; no data regarding participants with non‐Shigella dysentery (112) who were randomized according to the inclusion criteria. 7 patients were excluded from the culture Shigella positive 62 (5 from cotrimoxazole group due to drug resistance to the allocated drug and 2 others not mentioned).
Free of selective reporting?	Low risk	The study's prespecified outcomes, which were of interest in this review, have been reported
Free of other bias?	Low risk	The study appears to be free of other sources of bias