ORONO ? The Boston University softball team calls her Smiley. Albany parents wondered during a recent home game how she could seem to cheerful with two runners on base and no outs. Opposing players hate striking out and walking back to the dugout, glancing to the circle and catching that grin.

For University of Maine pitcher Jenna Merchant, smiling is just part of the game. She loves softball, and believes in showing it.

“I always have taken that approach,” Merchant said recently. “I can’t understand people who just stand out there like rocks. How can you not enjoy yourself? I just love it, I always have.”

Smiling also has been a way for Merchant to calm down her team when the Black Bears worry about their standout righty. But their worries have nothing to do with how many walks she’s allowed or how many runners are on base.

Merchant, a native of Sandy, Utah, suffers from a condition called Cyclic Vomiting Syndrome. Although she left her mark on the school records book with 394 career strikeouts, Merchant dealt with stomach pain even when she wasn’t in the throes of her illness.

In a series of circumstances completely unrelated to CVS, Merchant has had to end her pitching career early, although she’ll likely serve as a designated hitter in at least one game if the Black Bears can advance in the America East tourney, which starts today at Stony Brook, N.Y.

Coming off a junior campaign in which she was named the conference’s pitcher of the year, she pitched well early this season. But Merchant pulled a hamstring and then got word of the suicide of a high school friend, which sent her into a funk. A few weeks ago, Merchant took a ball off her right wrist. With the joint near her thumb still swollen, she figures she won’t make any more appearances in the circle.

So it’s a bit ironic that her injuries, and not CVS, have halted her pitching career.

CVS is a disease that typically affects children but can show up later in adulthood, Merchant said. She described CVS as a migraine in the stomach ? severe, debilitating nausea and vomiting that can last hours and even days. It usually appears at the same time in a cycle, such as once a month. There are a variety of treatments, including medication traditionally used for depression or bed-wetting, but Merchant said some medications she tried relieved the CVS but left her with chronic stomach pain.

Merchant first noticed monthly nausea when she was a sophomore in high school, but didn’t get a diagnosis until after she was in college. Originally recruited by Michigan State, Merchant landed in Maine because she saw a computer-generated picture on the UMaine Web site of the future Kessock Field with ivy growing on its proposed brick walls, just like Wrigley Stadium in Chicago, where her Pakistan-born father spent several years before moving to Utah.

Although the ivy and bricks never materialized at Kessock, Merchant flourished. As a freshman she was named to the America East first team and all-rookie team for her 17-11 record, 1.49 earned run average and team-high 145 strikeouts.

As a sophomore Merchant had 153 strikeouts, but there was an underlying reason for that increase. The medication she took for CVS made her too dizzy to field balls.

“I had more strikeouts my sophomore year because it was like a defense mechanism,” Merchant said. “I knew that if the ball came back to me I was dead. Now every time I tie my shoes [the team thinks] I’m sick because that year I spent so much time waiting for the blood to come back to my head. That was rough because obviously it interferes with how you play.”

Merchant never seemed to let CVS affect her.

“Pretty much when she crosses onto the playing surface she’s there for softball and lets everything else go aside,” said Black Bear interim head coach Michelle Puls, who served as an assistant during Merchant’s first three years. “She really stepped up a couple of times last year and the year before where you didn’t think she was going to perform and she was able to do that. Seeing that, a kid who’s had those struggles come in and do what she’s done, she’s an inspiration for our kids.”

Merchant’s last severe CVS episode occurred last fall. She landed in the hospital, where she caught pneumonia but still went back to Utah a few weeks later to run with seven other members of her family in the St. George Marathon.

Her injuries and off-field struggles have made for a disappointing senior season ? she’ll finish with a 4.20 ERA and a 3-4 record ? but Merchant graduated with her class last week and is putting the finishing touches on her honors thesis about the relationship between Walt Disney’s cartoon princesses and American women. She plans to take a year off to study for the law school entrance exam, work for her pharmacist father and run the St. George Marathon again.

Merchant, now 22, is also waiting out her CVS, which she said can disappear in young adulthood. It’s been a frustrating wait, but you’d never know from watching Merchant play softball.

“I think smiling is like my Samson with the hair,” she said. “It’s like my source of power. I’m so much better when I smile.”