Tabitha McMahon, top right, poses for a holiday photo with her daughter, mother and grandmother.

Editor’s Note: Tabitha McMahon is one of six CNN viewers selected to be a part of the Fit Nation Triathlon Challenge program. Follow the “6-pack” on Twitter and Facebook as they train to race the Nautica Malibu Triathlon with Dr. Sanjay Gupta on September 8.

Story highlights

Tabitha McMahon was diagnosed with ulcerative colitis, a inflammatory bowel disease

McMahon had emergency surgery to remove her large intestine

She's now determined to focus on nutrition, exercise to stay healthy for her family

“I knew you were going through this for a reason. I just didn’t know it would take so long.”

That’s what my mother said when I broke the news to her that I had been chosen for the 2013 CNN Fit Nation Team.

“I knew they would pick you,” she added. But she’s my mom, and therefore legally obligated to say that.

I choked up when I heard her words that morning. In them was the anguish and emotional hell she and my father had gone through, watching their middle daughter suffer for months on end. In them was the faith and optimism that I would live. In them was the unwavering hope that I would turn this experience into a positive; not just for me, but for countless others.

Her response prompted me to reflect on a part of my life I don’t often think about. A great deal of pain accompanies those memories. It was a time when, due to illness, leaving the house was the exception, not the rule. A time when it was not a question of if I would meet the medical deductible that year, but when. A time when my future was uncertain.

During my sophomore year at Indiana University, I suddenly became ill. After being hospitalized on Halloween, I was diagnosed with ulcerative colitis, a type of inflammatory bowel disease. The next two years were a blur of medications, hospitalizations, procedures and unpleasant side effects and complications.

When my GI doctor exhausted his treatment options, he referred me to the Cleveland Clinic where I had emergency surgery to remove my large intestine. Six months later, I had one more surgery to reverse an ileostomy and reconnect the J-pouch my surgeons had created.

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My mother and father went through so much while I was ill. Even then, at just 19, I somehow understood that it was easier to be the patient than the loved one of the patient.

Sure, I was hospitalized, poked and prodded. I had procedures, transfusions and surgeries. And there were days when it hurt like hell. If I was being honest with myself, I wasn’t completely sure I’d live to see my 20s.

But it was my pain and my physical burden, and I could carry it. Being a caregiver is so much worse.

My parents worried nonstop. Not just about me – they didn’t have the luxury to focus solely on my recovery. They had jobs and another daughter still at home who required their energy and attention. They felt helpless. They lacked the power to make everything better.

And that’s the real horror. Helplessness might be the most terrifying emotion.

What really struck me about my mother’s statement was its incredible amount of optimism. She knew in her heart that I would not just survive ulcerative colitis, but ultimately thrive. She believed that as a family, we would help others.

In the past 16 years, I’ve lost track of the number of people we have referred to the Cleveland Clinic or specific doctors. And my mother inherently knew that it was in my nature to want to pay it forward and to lead not by words, but by example.

As soon as I was released from the hospital following my last surgery, I moved across the country, intent on getting on with my life. Now that I’m a mom, I recognize how incredibly difficult that must have been for my own mother.

But she and my father loved me enough, trusted me enough and had enough faith to let me go out and live my life. That is, to this day, the greatest gift they have given me.

In the years since my abdominal surgeries, I’ve had several additional complications and health scares, ranging from ulcers in my small intestine to bowel obstructions to miscarriages.

Most recently was a nine-day hospitalization last January. My 7-year-old daughter visited me every day. Like kids do, she took it all in stride, more or less. However, there were moments where her concern and fear were obvious.

It was heartbreaking. She was trying to make sense of this new, albeit temporary, reality. Mom can’t come home. She has to stay in the hospital, connected to machines with medicine being pushed through an IV and weighing the merits and risks of another surgery.

It was a moment of clarity for me. I was compelled to take as much control of my health and fitness as possible. I don’t want to be absent from anyone’s life – not my daughter’s life and not my own.

I’m still processing my emotional response to my mother’s heartfelt words. Now I’m even more determined to seize this incredible opportunity – to focus on exercise and nutrition as a means of staying healthy. Not just for myself or my daughter, but for my mom.

I hope others will follow our Fit Nation team and choose to do the same.

Follow Tabitha on Twitter @TriHardTabitha