Pacemakers of the GIT are present in all, EXCEPT:

Pacemakers (interstitial cells of cajal), are mesenchymal cells with smooth muscle like features. They act as pacemaker of gastrointestinal tract by creating basal electrical rhythm which leads to contraction of the smooth muscles. They are absent in esophagus and proximal poion of the stomach. Ref: Ganong's Review of medical physiology, 22nd Edition, Page 480