A 45-year-old patient complains of abdominal pain and discomfort that occur in emotionally straining situations. Objectively, no changes were detected in the gastrointestinal tract. The complaints first arose over 10 years ago against the background of a severe alcohol poisoning. The patient has been repeatedly visiting gastroenterologists, who were unable to detect any significant changes. The prescribed therapy was ineffective. What is the most likely diagnosis in this case?