# Brussels Infant and Toddler Stool Scale

Using 1312 photographs of infant stool in diapers (1100 meeting quality criteria, of which 896 had majority agreement among three pediatric gastroenterologists as the reference set), the study trained 20 convolutional neural network models on Teachable Machine with an 85/15 training and internal-validation split and assessed agreement with specialists on the BITSS: the best seven-category model reached overall accuracy 0.56 with linear and quadratic weighted Kappa of 0.59 and 0.75, while a four-category grouping (constipated, formed, soft, liquid) reached accuracy 0.76 with weighted Kappa of 0.69 and 0.78, whereas agreement among the three specialists showed a Fleiss Kappa of only 0.24 and 24.7% complete agreement.

Using 1312 photographs of infant stool in diapers (1100 meeting quality criteria, of which 896 had majority agreement among three pediatric gastroenterologists as the reference set), the study trained 20 convolutional neural network models on Teachable Machine with an 85/15 training and internal-validation split and assessed agreement with specialists on the BITSS: the best seven-category model reached overall accuracy 0.56 with linear and quadratic weighted Kappa of 0.59 and 0.75, while a four-category grouping (constipated, formed, soft, liquid) reached accuracy 0.76 with weighted Kappa of 0.69 and 0.78, whereas agreement among the three specialists showed a Fleiss Kappa of only 0.24 and 24.7% complete agreement.