1.   Fractionated doses of abdominal radiation increase the frequency of giant migrating contractions and retrograde giant contractions.

2.   Giant migrating contractions are associated with transit of market over larger distances in a distal direction.

3.   In all spinal patients the distension evoked uninhibited giant rectal contractions.

4.   Giant contractions were always associated with enhanced internal anal sphincter relaxation and induced spontaneous balloon evacuation in nine patients.

5.   Giant rectal contractions were never seen in normal subjects.

6.   Both responses, however, were exaggerated in spinal patients, demonstrating giant contractions associated with deep anal relaxations and spontaneous expulsion of the balloon.