"He's fine, he just needs to control what he eats," said manager Joe Maddon. "It's very painful and it's unusual, but that's what he's got."
Howell has allowed one run in each of his past two outings after five straight scoreless appearances. Maddon said it should give Howell peace of mind to know what the injury is.
"You've got to just medicate it and maybe change your diet," Maddon said. "Not knowing what it is just plays on your mind. Now that we have definition, he feels a lot better about it."
Maddon said he would have a hard time dealing with the condition.
"He told me he's supposed to not eat red meats, eat seafood or drink red wine," Maddon said. "I would die in like three weeks."