I was 21 when I had my first colonoscopy. It was a wake-up call that I needed to change my lifestyle.

• Gabriella Parker, 25, has experienced digestive health issues since childhood.
• When she was 21, she had a colonoscopy for the first time.
• Having a colonoscopy served as the wake-up call she needed to make lifestyle changes to improve her health.

This as-told-to essay is based on a conversation with Gabriella Parker. It has been edited for length and clarity.

The American Cancer Society recommends adults with an average risk for colorectal cancer begin having regular colonoscopies at 45. I had my first colonoscopy when I was only 21.

I've struggled with constipation and bleeding with bowel movements since childhood. I would have a bowel movement maybe once a week, growing up. At primary care checkups, doctors would tell my parents, "Give her Metamucil" and other supplements. My parents said they'd try things but never changed my diet. My parents both worked and had other priorities to manage. Growing up, my diet consisted of highly processed foods, like fast foods, and a high-fat diet.

When I was 16, I decided to become vegan, but I was still eating a high-processed vegan diet, so the change didn't help my digestive issues. Even at 5'9 and living an active lifestyle, I did not use the restroom regularly. Feeling sluggish and bloated felt normal to me. The bleeding with bowel movements continued on and off through adulthood but got continuously worse with age.

I was heard by doctors when my symptoms got worse

When I had just turned 21, I went to my primary care doctor and said, "Nothing is working. I'm bleeding every time I use the restroom. Something's wrong." Thankfully, my doctor heard my concerns, and I was referred to a gastroenterologist who sent me for a colonoscopy.

The prep for a colonoscopy is worse than the procedure because you're flushing your whole system out. I remember drinking the larger-size MiraLAX and a little bit of Milk of Magnesia. I chugged all of that and used the restroom prior. A few of the nurses commented that I was too young to have a colonoscopy and asked about my symptoms.

I was scared going into the procedure because I didn't know what to expect, but everyone made me feel so comfortable. I had a chance to meet everyone who would be in the room. The procedure itself is very brief, and there's no pain as you're under anesthesia. When I woke up, they let me rest as long as I needed to and provided fluids. It was definitely a whole-day event.

They didn't discover any underlying health issues, but they did discover polyps and severe hemorrhoids, which they treated. The doctor said the hemorrhoids could have been playing a huge role in the bleeding.

The experience kick-started my lifestyle changes

When I was vegan, I ate a high-carb, highly processed diet. I've since changed my eating habits. I'm no longer vegan and focus on having a more well-rounded diet. I prioritize high-protein meals with tons of fruits, vegetables, and fiber. I don't restrict any foods, but I'm mindful of eating processed and sugary foods because I know my body doesn't feel great when I do.

I used to do a lot of strength training workouts, which put a lot of stress on the body. I've found that when my cortisol and stress levels are elevated, I don't use the restroom as frequently, so I try to prioritize a slower lifestyle. I now do all sorts of movements, like swimming and walking.

I also prioritized my emotional health post-colonoscopy. I realized I was always stressed out as a kid, and I think that played a role in my symptoms. I started therapy, I left my stressful corporate job, and I left a toxic relationship.

After the colonoscopy and lifestyle changes, now at 25, I experience bleeding or pain with bowel movements maybe once a year. When it does happen, I can connect it back to a bad diet or feeling super stressed out.

Physical, emotional, and mental health are closely related to digestive health and how the body responds to you.

Have an interesting personal story about your health or wellness? Get in touch with cgriffin@businessinsider.com.