How much control would someone with a SCI that resulted in a reflex bowel/bladder? (injury above T-12)
Not much, if any. A reflex bladder contracts involuntarily, leaving the person unable to control, or predict, the urine output. Catheterization is almost universal. Bowel controls is more hit or miss; given the fact that sensation is usually impaired or gone entirely for those with SCI, it can be difficult to sense when the bowels are full. Regimented, planned, regular bowel programs are standard in getting an SCI patient in a real-world environment.
*Of course, no two SCI are identical and certain injuries take totally different paths.