The Primary Purpose of the Position is: The primary purpose of this position is to assist the practitioner in gastro-intestinal endoscopic procedures. The Organizational Location of the Position is: GI Endoscopy Unit, Gastroenterology Section, at Dallas campus of the VA North Texas Health Care System (VANTHCS), Dallas, TX. Basic Requirements: Citizenship. Citizenship of the United States. (Non-citizens may be appointed when it is not possible to recruit qualified citizens in accordance with chapter 3, section A, paragraph 3g, this part.). Education. There are no specific educational requirements for this occupation. Education may be substituted for experience only at the GS-4 and GS-5 levels. See the grade requirements part of this standard for information regarding educational substitutio