Gastro-intestinal Biopotential Recorder by Means of Surface ELEctrodes

The goal of this clinical trial is to compare the gastro-intestinal biopotentials recorded with a homemade device using surface electrodes placed on the abdomen in healthy volunteers, Crohn's disease patients without fibrosis, Crohn's disease patients with fibrosis and in functional gastrointestinal disorders (FGID) patients. The main question it aims to answer is: • Is there any differences in the gastro-intestinal biopotentials between the different populations under study? It aims to answer two secondary questions: * Are the gastro-intestinal biopotentials comparable to the Harvey-Bradshaw Index, MRI and biological data for patients with Crohn's disease? * Are the gastro-intestinal biopotentials comparable to Rome IV criteria for functional gastrointestinal disorders patients? Participants will undertake two recordings made with the device. The first one will last 1 hour and 30 minutes and will occurs while the participants are fasting. Then, the participants will eat a standardized meal. Finally, the second recording will take place after the meal ingestion and will last 1 hour and 30 minutes while the participants are in postprandial state.