Intussusception Surveillance After Rotarix Introduction in Mexico

Inclusion Criteria: A child's clinical episode will be defined as an IS case and deemed eligible for the study if he/she meets the following criteria: * Subject is an IMSS affiliate * Subject is being treated/has been treated/has been referred for treatment at one of the IMSS hospitals/medical facilities with IS during the study period. * Male or female child is \<one year of age at the time of diagnosis of the IS (child becomes ineligible on the day of their first birthday) * Subject is diagnosed with definite IS based on the Brighton criteria * Written informed consent is obtained from the parent/guardian/legal representative of the subject Subjects meeting the above criteria will be eligible for inclusion in this study regardless of whether or not the subject has had a radiographically or surgically confirmed case of IS prior to the current episode. Exclusion Criteria: Not applicable