Gastroscopy is not usually performed incidentally to check the throat.
Gastroscopy is a common examination device to check the condition of the digestive tract, which uses a soft, slender tube to reach the esophagus from the mouth to the stomach to observe the stomach. This test allows direct observation of the actual condition of the examined area, and also allows for sampling of the suspicious part for further pathologic examination and definitive diagnosis.
Checking the throat usually uses laryngoscope, which is an examination method often used in otorhinolaryngology, which enters through the nostrils and examines the nasopharynx, oropharynx, laryngopharynx and larynx. This examination method allows direct observation of the actual condition, sampling of the suspicious part and also local administration of medication.
There are some differences between gastroscopy and laryngoscopy, so gastroscopy is usually not an incidental examination of the throat.