SAN DIEGO -- Chan Ho Park spent Monday night in Scripps Clinic, where he is to be tested on Tuesday in an attempt to discover the source of intestinal bleeding that returned on Monday, forcing him to be scratched from his start against the Dodgers at PETCO Park.

"There's bleeding of the lower gastrointestinal area," Padres manager Bruce Bochy said. "That's all we know. I don't have a feel for it, but obviously there's a concern. I know they're frustrated they couldn't find anything the first time. That's why they're doing another test."

Park, 33, was durable and productive in 19 starts before his intestinal bleeding surfaced in late July, going 7-7 with a 4.68 ERA.

Bochy said, "If it gets to the point where we don't think he should pitch, he won't pitch."

Park had gone five innings in a loss at Houston and 5 1/3 innings in a no-decision against San Francisco since returning from the disabled list on Aug. 11. He had beaten the Dodgers, his original club, 7-3, at Dodger Stadium on July 25, two days before the illness caused him to leave Denver for a round of exams in San Diego.

"He developed similar symptoms with the bleeding," said Bochy, who was informed of Park's discomfort at 10:30 a.m. on Monday. "He was losing some blood, and we're trying to figure out what's going on."