A 60-year-old patient complains of nearly permanent sensation of heaviness and fullness in the epigastrium, which increases after eating, foul-smelling eructation, occasional vomiting with food consumed 1-2 days ago, weight loss. 12 years ago he was first found to have an ulcer of pyloric channel. The patient has taken ranitidine for periodic hunger pains. The patient's condition has been deteriorating over the last 3 months. Objectively: splashing sound in the epigastrium is present. What kind of complication is it?