By Charlotte Triggs
January 19, 2009 12:00 PM

After suffering a burst ulcer in 2006 that resulted in the removal of part of her stomach, Kristen Johnston spent two months in the hospital—and ended up losing a shocking 60 lbs., setting off a round of eating disorder rumors. Although the 6-ft. Johnston, 41, admits, “I was way too thin,” her doctor Barry Cohen explains that the star’s emergency stomach surgery interfered with the hormone responsible for hunger. Now “she actually has to make a conscious effort to eat,” he says. Here Johnston, who appears in this month’s Bride Wars, shares her long struggle back to health.

PEOPLE: When you look at pictures of yourself from last year, what do you see?

Johnston: People had been telling me, “You’re really thin,” but I just didn’t realize how thin. I really was too skinny. I get it—I’m not like, “I looked great!” I realized it when I saw the pictures of myself: Of course people think I’m sick. I looked sick. Hopefully, I will never look like that again.

Did the public skepticism of your story upset you?

Johnston: It bugged me that people thought all of a sudden, at 40, I’m going to start throwing up because I care about my weight. The reason I got so thin is the opposite of vanity. But people doubted my story; they couldn’t imagine it wasn’t a drug habit or eating disorder.

You said cutting out alcohol was in part responsible for the weight loss, right?

Johnston: Before the ulcer, I was living an unhealthy life, drinking way too much, and that’s why I got bloated. After two months in the hospital, I knew I had to change. I got sober, and I’m so happy I made that decision.

But really: You didn’t have any issues with food?

Johnston: I have never had an eating issue. I don’t diet. I drink regular Cokes and I have egg-and-cheese sandwiches for breakfast. The problem is, my stomach no longer indicates to me whether it’s hungry—when food is in front of me, I eat it, but I’m never hungry. Ever. I went to the doctor about it. He says my stomach will eventually get back to normal.

How is your weight now?

Johnston: I’ve really worked hard to gain weight back. I can go seven hours and be like, “Oh, right: food!” I’ve never done that before. So I drink two Ensure a day just to make sure I [get enough calories]. I’ve gained like 25 lbs. so far. I can’t believe I have to work at it.