Background: Gastric glitch is a new functional disease characterized by severe and transient epigastric pain occurring after challenges such as drinking alcohol and eating specific foods. Aims: In this N-of-1 trial, we first characterized the clinical and gastric tomographic images of a patient with gastric glitch highly reproducible after alcohol challenging, and then tested the effect of prucalopride and buspirone on the prevention of gastric glitch crises.

Objective: To evaluate the effect of prucalopride and buspirone, compared to placebo, in the prevention of gastric pain crises, in a double-blind clinical trial of a single patient. Methods: Female, 35 years old, with signed consent to participate in the study, received 15 capsules to take 1 capsule 60 minutes before ingesting 200 ml of red wine at home (≈20 grams of alcohol), twice a week, according to her routine food, totaling 15 meals. Thus, the experimental phase lasted about eight weeks. The 15 capsules contain placebo (5 capsules), prucalopride 2 mg (5 capsules) or buspirone 10 mg (5 capsules), prepared by a specialized pharmacy in such a way that their physical characteristics do not allow the identification of which agent is being administered, neither by the patient nor the investigator controlling the trial (double-blind). The aforementioned pharmacy generated a code for each pill, randomly, and provided a sealed list with the 15 codes and their respective drugs, for disclosure after the end of the study. The patient was instructed to record in a standardized diary the occurrence of pain crises after the wine challenge, as well as their duration and intensity (Likert 0 to 10: maximum pain), and accompanying symptoms. The patient was asked to contact the researchers directly (WhatsApp) throughout the trial, to clarify any doubts or need for some assistance due to the occurrence of symptoms related to the study. The study statistics will be descriptive in terms of pain events, and the effect of the drugs will be evaluated in a statistical model suitable for the N-of-1 trial. Prucalopride is a 5-HT4 receptor agonist that accelerates gastric emptying, while buspirone is a 5-HT1A receptor agonist that enhances gastric accommodation function. The presumed pathophysiology underlying the patient's pain is retention of wine in the gastric lumen, causing pain. Stimulating gastric emptying with prucalopride or increasing the accommodation of the gastric fundus with buspirone could prevent or alleviate the pain crisis.

Inclusion Criteria:

• adult patient suffering from severe gastric pain after ingestion of a small amount of wine

Exclusion Criteria:

• N/A (N-of-1 trial)

Identical capsules containing prucalopride, buspirone or placebo.