A truck driver's claim of a blackout caused by severe diarrhea is not sufficient to shield him from a lawsuit for rear-ending another vehicle, the Michigan Supreme Court ruled.

James Birkenheuer was driving a truck from Cincinnati to Novi, Mich. He took a bathroom break at a rest stop in Canton, Mich., but 20 minutes later, his digestive problems flared up again.

Birkenheuer said he started to slow down when he saw the plaintiff's car, but he blacked out due to the diarrhea. The impact of the collision jarred him back into consciousness.

The trial court granted Birkenheuer summary judgment, since the doctor's diagnosis supported his explanation. However, Justice Taylor upheld the Court of Appeals' reversal of the decision.

"There is evidence that defendant should have known he was not feeling well when he continued driving after his urgent stop at the Canton rest area," Taylor wrote. "This creates a genuine issue of material fact regarding whether defendant's emergency was totally unexpected."