Patient description: A 17 year old boy complains of vomiting, non-bloody diarrhea, abdominal pain, fever, chills and loss of appetite for the past 3 days. He ate a salad at a restaurant prior to his diarrhea onset. Physical exam was remarkable for pallor, jaundice, and diffuse abdominal tenderness. Lab results were as follows: Hemoglobin: 9.7 g/dL Platelet: 110,000 /cu.mm Creatinine: 3.6 mg/dL blood urea nitrogen (BUN): 73 mg/dL direct bilirubin: 2.4 mg/dL lactate dehydrogenase (LDH): 881 IU/L (normal: 110-265 IU/L) Peripheral blood smear showed a moderate number of schistocytes and helmet cells. Shiga-like toxin-producing E. coli (STEC) stx1/stx2 were found in stools. He has no other underlying disease and he is not on any medications.

Clinical trial eligibility criteria: eligible ages (years): 1.0-12.0,  Diarrhea Chronic Diarrhea Acute Diarrhea Diarrhea, Infantile Children of either sex aged between 1-12 years (inclusive); 2. Evidence of acute (onset <7 days prior to screening visit), prolonged (onset between 7 and 14 days prior to screening visit) or chronic (onset >14 days prior to screening visit) diarrhea Acute/Prolonged Diarrhea is defined as at least 3 evacuations of loose or watery stools (stools type 6-7 of Bristol scale) occurring in the 24 hours preceding the screening visit Chronic Diarrhea (>14 days duration), defined by passage of loose or watery stools (Bristol score 6 or 7) with or without an increase in frequency of bowel movements; 3. Evidence of mild to moderate dehydration, defined as a score 1-4 in the Clinical Dehydration Scale; 4. Parents/legal guardians availability to fill on a daily basis the electronic daily diary by a smartphone/tablet/laptop. 5. Parents/legal guardians* have given a written informed consent for participation in the study at the time of enrolment or before. The parent/legal guardian should also have agreed to bring the child for the visits scheduled in the protocol and to provide the requested information during the telephonic follow-up visit; 6. Parents/legal guardian able to understand the full nature and the purpose of the investigation, including possible risks and side effects, able to cooperate with the Investigator and to comply with the requirements of the entire investigation (ability to attend all the planned investigation visits according to the time limits included) based on Investigator's judgement  Children of female sex having started menarche; 2. Evidence of severe dehydration, defined as a score > 4 in the Clinical Dehydration Scale; 3. Known hypersensitivity to any of the components (active ingredients or excipients) of the investigational product; 4. Severely malnourished patients, defined as those patients with body weight < 50% for age; 5. History of immune diseases or conditions known to producing immunodeficiency (AIDS, other congenital immunodeficiency syndromes, anticancer drugs, etc.); 6. For acute/prolonged diarrhea only, patients who have received any of the following treatments within the 2 weeks before the screening/baseline visit Drugs with adsorbing properties, e.g. kaolin, pectin, bismuth subsalicylate Drugs that modify intestinal secretions, e.g. racecadotril Drugs that modify intestinal motility, e.g. opiates such as loperamide, atropine and other anti-cholinergic agents) Laxatives Antibiotics 7. History of seizures due to known or unknown causes; 8. Parents/legal guardians' refusal or inability to give written informed consent to participate in the study; 9. Parents/legal guardians who, in the opinion of the Investigator, are unable to fill up the electronic patient diary; 10. Patients who may not be possible to come for the scheduled visits; 11. Patients who have participated in any other clinical trial in the last 3 months prior to the start of the study