CAPT EXPERIENCED SEVERE BACK PAIN WHILE ENROUTE TO LAS AT FL270. TURNED ACFT CTL OVER TO THE FO AND CONTINUED TO DESTINATION.

Narrative

ON THE DAY OF THIS SITUATION 2 LEGS OF THE TRIP WERE ALREADY COMPLETED. OUR FLT DEPARTED SAN FRANCISCO NORMALLY ENRTE TO LAS VEGAS. APPROX IN THE AREA OF LIDAT INTXN; THE PLT IN COMMAND (PLT FLYING) STATED HE WAS EXPERIENCING SOME DISCOMFORT IN THE LOWER LEFT BACK AREA. SHORTLY AFTER THIS; THE CAPT REQUESTED THAT I FLY THE ACFT TO A LNDG IN LAS VEGAS. AT APPROX 50 NM FROM THE ARPT; THE CAPT REQUESTED AN AMBULANCE MEET THE ACFT AS A PRECAUTIONARY MEASURE. THE REMAINDER OF THE FLT WAS CONDUCTED IN A ROUTINE MANNER; ALL CHKLISTS ACCOMPLISHED; NO DEVIATIONS FROM FLT PROFILES. ON OUR ARR AT THE GATE; THE AMBULANCE MET THE ACFT IN A LOW PROFILE MANNER; AND AFTER ALL PAX WERE DEPLANED THE CAPT WALKED TO THE AMBULANCE UNASSISTED. AN EMER WAS NOT DECLARED AS THE CAPT WAS CONSCIOUS AT ALL TIMES AND REMAINED IN COMMAND/DECISION MAKING AUTHORITY. BECAUSE OF THE RANDOM FACTOR INVOLVED IN THE SITUATION; I CANNOT THINK OF A SOLUTION OTHER THAN PERSONAL JUDGEMENT TO CORRECT THE SITUATION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING. THERE WAS NO MEDICAL HISTORY OF PROBS THAT ANYONE WAS AWARE OF FOR THE CAPT INVOLVED. F/O DOES NOT THINK THE PAX WERE EVER AWARE THAT THE CAPT BECAME ILL AND THINKS THIS WAS HIS 1ST PROB WITH A KIDNEY STONE.