This study aimed to describe the process of construction, validation, and usability of the chatbot ESTOMABOT to assist in the self-care of patients with intestinal ostomies. Methodological research was conducted in three phases: construction, validation, and usability. The first stage corresponded to the elaboration of a script through a literature review, and the second stage corresponded to face and content validation through a panel of enterostomal therapy nurses. In the third phase, the usability of ESTOMABOT was assessed with the participation of surgical clinic nurses, patients with intestinal elimination ostomies, and information technology professionals, using the System Usability Scale. The ESTOMABOT content reached excellent criteria of adequacy, with percentages of agreement equal to or greater than 90%, which were considered adequate, relevant, and representative. The evaluation of the content validity of the script using the scale content validity index/average proportion method reached a result above 0.90, and the Fleiss κ was excellent (P < .05). The overall usability score of the chatbot was 81.5, demonstrating excellent usability. The script, developed and incorporated into the ESTOMABOT prototype, achieved satisfactory content validity. The usability of the chatbot was considered to be good, thereby increasing the credibility of the instrument.