The aim of our study to compare the proportion of patients who develop SARS-CoV-2 disease in 3 groups: patients undergoing a abdominal ultrasound examination in a Specialty Center, patients undergoing endoscopic procedure in a third level hospital with CoronaVirus Disease (COVID-19) hospitalization plants and patients who make a telephonic visit (do not go to the hospital) in the digestive system service.

Patients will undergo a telephonic interview 48-96h before the procedure where will ask about the presence of symptoms suggestive of SARS-CoV-2 infection. Optionally, they will also be carried out a scan (PCR) to detect infection 48-96h before procedure, withdrawing from the study patients with positive PCR or infection suspected by clinical data according to the questionnaire, after evaluating the responses to the questionnaire by one of the members of the research team.

Endoscopic examinations will be carried out according to the recommendations of the Spanish Society for Digestive Endoscopy (SEED). The patient will perform a hand wash with solution hydroalcoholic before entering the endoscopy room, and you will be placed a surgical mask and gloves. Staff close to the patient will carry FFP2 mask, exceptionally surgical mask, gown (waterproof in high-risk examinations as established in the SEED guidelines), hat, nitrile gloves and face shield or safety glasses (reusable) and shim covers. The examinations will be carried out using sedation guided by endoscopist according to current clinical guidelines.

Ultrasonographic examinations (US) will be carried out according to clinical guideline. The examinator will wear a filtering face pieces 2 (FFP2) mask, exceptionally surgical mask, gown, cap, nitrile gloves and face shield or goggles safety (reusable) and shoe covers. The gel bottle, the transducer and the gurney will be washed before each US with low level disinfectant.

Patients who meet the inclusion criteria and do not have any exclusion criteria will be invited to participate in the study. The patients who agree to participate will complete the informed consent according to the law 41/2002 of patient autonomy without for that reason alter the relationship with your doctor or cause any harm to your treatment. The monitoring period will have a maximum duration of 17 days. It will consist of a telephone control through a pre-established checklist. In case of any positive answer to the questionnaire, it will be completed the study through the consultation of the investigators by means of a polymerase chain reaction (PCR).

Inclusion Criteria:

• Patients scheduled for an ambulatory endoscopy, an ambulatory abdominal ultrasound, or a telephonic visit Age younger than 18 years.

Exclusion criteria:

Refusal to sign the informed consent Immunosuppression (steroid treatment with a dose of 20 mg or more of prednisone daily, azathioprine, cyclosporine, mercaptopurine, methotrexate, mycophenolate, tacrolimus, everolimus, chemotherapeutic agents, anti-tumoral necrosis factor (TNF)-α drugs or other biological treatments for inflammatory bowel disease) Immunodeficiency due to a non-pharmacological cause (HIV, hematological dyscrasias, primary immunodeficiencies ...) Previous confirmed diagnosis (by PCR or serology) of SARS-CoV-2 disease. Diagnosis of previous suspicion (documented in the medical history by a physician) of SARS-CoV-2 disease.

Previous clinical picture compatible with SARS-CoV-2 in the previous 2 months (defined as any positive response to the check-list questionnaire contained in Annex III) Cognitive impairment or hearing impairment preventing the phone visit Habitual residence outside the province of Valladolid Ultrasound interventionism (liver biopsy, ultrasound-guided paracentesis, biliary drainage ...)

Patients scheduled for an ambulatory endoscopy, an ambulatory abdominal ultrasound, or a telephonic visit