Esophagogastroduodenoscopy (EGD) is the main examination in the upper gastrointestinal field. Aspiration pneumonia may happen if choking occurs during the EGD insertion, and the exam quality and efficacy may be affected if gag reflex occurs. The endoscopist may terminate the exam to avoid complications if the patient could not obey the orders. To reach the high quality of EGD examination and to avoid possible complications, the patient's comfort and compliance during the EGD examination are important. Sedation using propofol can improve the patient's comfort and compliance. However, in patients unsuitable for systemic anesthesia, local lidocaine spray at pharynx is performed instead. Until now, there is no standardization of the waiting time between lidocaine spray and the initiation of EGD. This study aimed to investigate the optimal timing of the initiation of esophagogastroduodenoscopy after lidocaine spray.

This study compares the 1-minute waiting time and 3-minute waiting time between the lidocaine spray and the EGD initiation. During the topical anesthesia stage, investigators give local spray with 6 puff on pharynx at the 0 minute in both groups. After the waiting time, EGD is inserted.

The baseline heart rate and blood pressure were recorded before EGD and during the EGD passing through pharynx respectively. After the whole procedure, enrolled patients will fill in the EGD quality questionnaire.

Through this study, investigators can figure out whether 1 minute or 3 minutes may be the optimal waiting time after lidocaine spray.

Inclusion Criteria:

• Eligible participants included patients aged ≥ 20 years who scheduled EGD from OPD for dyspepsia, peptic ulcer disease, GERD, subepithelial lesion evaluation, and diarrhea

Exclusion Criteria:

• GI bleeding
• endoscopic submucosal dissection due to prolonged scheduled procedure time
• patients from emergency department or ward

IPD will be shared after publication

Sealed and ordered envelope will be opened by assistant and the allocation was written on it. After then, lidocaine spray will be administered. The operator will be informed to prepare 30 seconds before the EGD initiation.