Supragastric Belching Does Not Cause Stomach Sounds—It Involves Only the Esophagus and Pharynx
Supragastric belching cannot cause stomach sounds because the air never reaches the stomach; instead, air is sucked or injected into the esophagus from the pharynx and immediately expelled orally without entering the gastric cavity. 1, 2
Mechanism Explaining Why Stomach Sounds Don't Occur
In supragastric belching, air movement is confined to the upper digestive tract through two distinct mechanisms: the air-suction method (where air flows through a pressure gradient from upper esophageal sphincter relaxation) and the air-injection method (where elevated pharyngeal pressure pushes air into the upper esophagus). 1
The air never descends past the esophagus into the stomach, making gastric sounds physiologically impossible with this type of belching. 3
This contrasts sharply with gastric belching, where air originates from the stomach and travels upward through transient lower esophageal sphincter relaxation—a mechanism that could theoretically be associated with gastric sounds. 1, 4
Distinguishing Features of Supragastric Belching
Supragastric belching occurs in approximately 3.4% of patients with upper GI symptoms and is strongly associated with anxiety and psychological factors. 1, 2
The behavior characteristically stops during sleep, distraction, or when speaking, providing clear evidence of its behavioral and learned nature rather than a physiologic gastric process. 1, 2
High-resolution esophageal manometry with impedance monitoring definitively differentiates supragastric from gastric belching by demonstrating that air flow in supragastric belching occurs more quickly, is independent of esophageal peristalsis, and never reaches the stomach. 1, 4
Clinical Implications
If a patient reports both excessive belching and stomach sounds (borborygmi), these are separate phenomena—the stomach sounds likely originate from intestinal gas movement, aerophagia (where swallowed air does reach the intestines), or normal digestive processes. 1, 3
Aerophagia should be distinguished from supragastric belching: in aerophagia, excessive air swallowing increases intragastric and intestinal gas, leading to bloating, distention, flatulence, and potentially audible bowel sounds, with belching being less prominent. 1, 5
The primary symptoms of aerophagia are bloating and abdominal distension with excessive intestinal gas visible on plain abdominal radiographs, whereas supragastric belching presents as isolated excessive belching without significant intestinal gas accumulation. 3
Common Diagnostic Pitfall
- Do not assume all belching involves the stomach—impedance-pH monitoring is essential to differentiate supragastric belching (esophageal air movement only) from gastric belching (stomach-originated air), as this distinction fundamentally changes treatment from behavioral therapy to acid suppression respectively. 5, 2, 4