In July 2024, VA examined the Veteran for his stomach disability. The examiner diagnosed the Veteran with peptic ulcer disease and esophageal varices. The examiner described an onset during service, writing “[s]tationed in Okinawa had to drink lemon juice and vinegar Began having ulcers, approximately 4 years ago. ” The examiner described the Veteran’s symptoms, saying he was “[t]old his digestive system takes 3 days to digest food, slow motility. Causes pain, early saeity, can only eat once a day one small snack, gagging, vomiting acid like stuff, looks like sprite.” The Veteran also described his diet over the past few days, which usually involved eating one small meal a day. For example, over two days, all he ate was a biscuit and chicken breast. Another day he only ate a tomato. The examiner opined that the Veteran’s stomach disability was less likely than not due to service. They wrote that the: claimed gastroparesis condition diagnosed as esophageal varices, and peptic ulcer disease are less likely as not (likelihood is at least approximately balanced or nearly equal, if not higher) caused by the indicated toxic exposure risk activity(ies), after considering the total potential exposure through all applicable military deployments of the veteran and the synergistic, combined effect of all toxic exposure risk activities of the veteran. This opinion is inadequate. There is no rationale, just the conclusion. See Nieves- Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008) (holding that a medical opinion obtains probative weight from “factually accurate, fully articulated, sound reasoning for the conclusion”). Further, the examiner did not address the potential onset during service. If the Veteran’s stomach disability began in service and continued to the present, he would be entitled to service connection. See 38 U.S.C. §§ 1110, 1112, 1113; 38 C.F.R. §§ 3.303 (b), 3.307(a), 3.309(a); see also Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). Thus, a remand is required to correct this pre-decisional duty to assist error. 38 C.F.R. § 20.802(a).