Brian Austin Green and his pregnant girlfriend Sharna Burgess sat down for an interview with “Good Morning America”, which aired Thursday.

The couple opened up about Green’s recent health scare with ulcerative colitis, an inflammatory bowel disease that left him bedridden for about six weeks.

Although Green, 48, has “dealt with ulcerative colitis a few times,” this was Burgess’s first time seeing him deal with the illness, which he says is a “real rough experience.”

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“I didn’t realize how debilitating it was until I saw him and watched weight drop off him,” Burgess, 36, said.

The actor revealed that he lost 20 pounds.

The mother-to-be recalled, “I was supportive and loving and [like], ‘I’m here for you,’ and internally fearful for how long does this go on for?” noting that she’s “still learning” about Green’s illness.

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In an effort to better live with the disease, the “Beverly Hills, 90210” alum has changed his diet by avoiding “gluten and dairy as much as possible.”

“It’s really just dietary, like, as long as I can keep things within my system that my body doesn’t think I’m poisoning it with, then it doesn’t fight back,” Green explained. “I would eat food, and literally it was like, my body didn’t process any of that.”

According to the Mayo Clinic, ulcerative colitis is “an inflammatory bowel disease (IBD) that causes inflammation and ulcers (sores) in your digestive tract. Ulcerative colitis affects the innermost lining of your large intestine (colon) and rectum.”

Last month, Green revealed he was suffering from the disease in a candid Instagram video in which he thanked his “amazing” girlfriend.

Speaking on the arrival of their first child together, Burgess, who is 33 weeks pregnant, said she “always knew I wanted to have kids because that was a deal-breaker for me.”

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“One of the things I fell in love with about [Green] was watching him be a dad and the way he parents. I thought, It would be so incredible to raise a child with him,” the “Dancing With The Stars” pro told “GMA”.

This will be Green’s fifth child, while, for Burgess, it’ll be her first.