Seventy-six newborn Holstein calves (44.4 ± 6.15 kg BW) were involved in this study from birth until 21 d of age. Within 2 h after birth, calves received 4 L of maternal colostrum via an esophageal tube. The following 3 meals consisted of 2 L of late colostrum (or transition milk). After that, calves were fed 1.5 L of milk replacer (22.9% CP, 20.1% fat) twice daily. Calves were considered diarrheic when showed fecal scores ≥3 for 3 consecutive days. Then, data from a random subset of 30 calves (45.9 ± 5.47 kg BW), 15 that never had diarrhea and 15 that had diarrhea were used to assess potential associations between intestinal permeability and incidence of diarrhea. On 0, 7, 14 and 21 d of life, intestinal permeability of calves was measured by dosing 2 markers (lactulose and D-mannitol) and assessing their concentration in serum by ultra-high performance liquid chromatography-mass spectrometry. Plasma IgG was measured at birth and at 6 and 24 h after first colostrum intake and efficiency of IgG absorption calculated. Plasma and colostrum IgG contents were determined by radioimmunoassay and bacterial load in colostrum samples by colony counting. Data were analyzed with a mixed-effects model for repeated measures. All diarrhea incidences occurred between 7 to 14 d of study. Overall colostrum quality was good, with an IgG content >50 mg/mL but total bacterial load was high (>100,000 cfu/mL). However, there were no differences in these 2 parameters between colostrums consumed by calves that did and those that did not incur diarrhea. Also, efficiency of IgG absorption was similar for all calves (~16%). However, intestinal permeability was increased in diarrheic compared with healthy calves. Diarrheic calves had greater (P < 0.01) lactulose serum concentrations (15.3 ± 0.37 µg/mL) than healthy calves (8.4 ± 0.37 µg/mL). Furthermore, diarrheic calves tended (P = 0.06) to have a greater lactulose to D-mannitol ratio (1.26 ± 0.16) since birth until 21 d of life than healthy calves (0.81 ± 0.16). In conclusion, calves correctly immunized that develop diarrhea may be predisposed to suffer scours due to altered intestinal permeability right from birth.