A typical single swallow + regurgitation peak + secondary swallow of a person with Zenker's diverticulum (MS, SUB and INF locations). The complete swallow (2.5–4.5 period) is slightly longer than the normal swallow. The SUB peak is normal, MS peak is high and appears in front of the SUB peak, LSM is normal. After a short pause (4.5–5.5) regurgitation peaks appeared with high INF line and low MS and SUB lines (5.5–9 period). Then the secondary swallow of the regurgitated bolus followed with high SUB peak (9.5–11).