Background : Diarrhoea is a significant cause of morbidity and mortality in foals. However, further research is needed to understand the occurrence of pathogens in both single and coinfections among extensively raised foals, with and without diarrhoea. Hypothesis/Objectives : Our hypothesis is that foals with diarrhoea have a greater prevalence of organisms detected in coinfections. Therefore, this study investigated the major microorganisms associated with diarrhoea in foals with and without diarrhoea. Study design : A total of 200 foals (100 diarrhoeic and 100 nondiarrhoeic), up to 1 year of age, were included in this study. Methods : Faecal samples were analysed for the detection of Clostridioides difficile (bacterial culture and toxin A/B detection), Clostridium perfringens (bacterial culture and genotyping) and Salmonella spp., Rhodococcus equi, Lawsonia intracellularis, Neorickettsia risticii, Enterococcus durans, Giardia duodenalis, Cryptosporidium spp. , rotavirus A and coronavirus (real-time PCR). Results : At least one enteric agent was detected in 85% and 70% of diarrhoeic and nondiarrhoeic foals, respectively. Codetection was significantly more frequent in the diarrhoeic group (27 singly detected organisms vs. 58 codetected organisms) than in the nondiarrhoeic group (37 singly detected organisms vs. 33 codetected organisms) (P = 0.0079). Salmonella spp., C. difficile (and A/B toxin gene detection) and Cryptosporidium spp. were significantly associated with foal diarrhoea. Conclusions and clinical relevance : The detection of multiple agents in foals with diarrhoea highlights the complexity of diagnosis and the potential interaction between agents in the multifactorial aetiology of this condition.