Table 1.

Key Characteristics of HAPC

Defined by high amplitude (variable threshold among studies) and presence of propagation; amplitude is higher in the prepped than unprepped colon Occur spontaneously, in response to pharmacological agents or colonic distention Increase upon awakening, are much more common during the day, and increase after meals A majority originate in the proximal colon; most do not propagate beyond the midcolon and fewer than 5% reach the rectum Can transfer colonic contents over long distances, can be associated with internal anal sphincter relaxation, and can precede defecation HAPC are reduced in slow transit constipation and increased in diarrhea predominant IBS and may explain disturbances of colonic transit in these conditions Useful for quantifying colonic motor function in chronic constipation