A diver with renal stones or infection poses a problem as to the differential diagnosis of renal colic and pain from infection and the symptoms of decompression sickness.
Stones and stents for drainage of urine are not affected by depth/pressure and should not in themselves be a reason not to dive. However, medications taken to relieve pain and spasms and to prevent reflux (such as Detrol) can have side effects that in theory could pose problems for the diver. Drowsiness, from any cause can be additive to the ever present effects of nitrogen narcosis. Detrol also can interact with other medications such as some antibiotics.
The diver should carefully document symptoms prior to your dives and observe and note any changes during and after the dive. Advise your divemaster and your buddy of your symptoms so that you will have a disinterested observer. The problems that would be encountered by the commercial diver in a saturation situation with renal colic would be considerable. The sport diver at remote dive sites is also placed in jeopardy.