Diarrhea is one of the most common gastrointestinal disorders affecting calves and represents a major cause of economic loss in the cattle industry. This study was conducted to assess the clinical fecal score, hematobiochemical alterations, and oxidative stress markers in pre and post weaned calves diagnosed with bacterial diarrhea. A total of 70 calves were included in the survey, comprising 10 healthy calves (control) and 60 diarrheic calves aged from 1-day old to 1-year-old. The diseased calves exhibited clinical signs including diarrhea, anorexia, weakness, dullness, unsteady gait, pale mucous membranes and varying degrees of dehydration. In this study, protein profiles, electrolyte and mineral alterations, liver function parameters, cortisol levels, CRP, malondialdehyde, and glutathione peroxidase activity were evaluated. The results revealed a higher prevalence of diarrhea among pre-weaned calves, with male calves being more frequently affected. Bacteriological analysis identified Escherichia coli, Salmonella spp., Proteus mirabilis, Proteus vulgaris, and Shigella spp. as the predominant pathogens. 20 diseased and 10 healthy calves were subjected to further analysis. Hematological findings in diarrheic calves showed a significant reduction (p>0.05) in total RBCs and Hb concentrations, accompanied by a significant increase in PCV%, WBCs with neutrophilia. Biochemical analysis of both pre and post weaned diarrheic calves revealed lower levels of protein profile parameters, Na, and Ca along with elevated K and Cl concentrations. P level was significantly decreased in post weaned calves only. Furthermore, diarrheic calves of both groups exhibited elevated levels of C-reactive protein (CRP), cortisol, ALT, AST and malondialdehyde (MDA), along with a marked decrease in glutathione peroxidase (GPX). In conclusion, diarrheic calves in pre and post weaning periods are susceptible to hematological, biochemical and oxidative status alterations. However, care must be given to calves in pre-weaning stage because of their greater susceptibility to diarrhea.