ACFT NOT REFUELED ON QUICK TURN AROUND.

Narrative

DURING A 'QUICK TURN' -- SCHEDULED GND TIME OF ONLY 20 MINS. WE RUSHED THE CHKLISTS AND GOT OUT ON TIME ONLY TO DISCOVER ON TAXI THAT WE NEVER GOT FUELED FOR THE NEXT FLT. WE RETURNED TO GATE FUELED AND PROCEEDED WITHOUT INCIDENT. DURING THE TURN AROUND; I WENT INSIDE THE TERMINAL WHILE THE FO DID THE WALK AROUND. UPON RETURN; I SAW A FUEL SLIP AND ASSUMED THE FO CHKED IT. HE THOUGHT I CHKED IT. IT WAS THE SAME FLT NUMBER AS IT WAS A THROUGH FLT. YET IT WAS FROM OUR EARLIER LEG. I HAD IT IN MY MIND THE FUEL WAS CHKED AND WE RUSHED THE BEFORE START CHKLIST. AS THE GND AGENT CLOSED THE DOOR AND OUR FIRST FLT ATTENDANT CAME TO COCKPIT WITH PAX COUNT. WE PUSHED BACK AND STARTED TAXI. WHILE ENRTE TO RWY; WE NOTICED A CONFLICT BTWN FLT PLAN TOW AND WHAT AN FMC WT SHOWED WHILE SETTING TKOF BUGS. WE WERE INVESTIGATING WHERE THE PROB WAS WHEN TWR TOLD US OUR OPS WANTED TO TALK TO US. THEY ENQUIRED ABOUT WHETHER WE'D BEEN FUELED AND OUR INITIAL REACTION WAS YES BECAUSE WE HAD THE FUEL SLIP YET THE GAUGES DIDN'T MATCH SO WE RETURNED TO THE GATE FOR MORE FUEL. MY CHKLISTS WILL NOT BE RUSHED IN THE FUTURE!