Briony revealed that the pair were enjoying a lazy Sunday in bed when she began getting pain in her back and stomach.
Unaware of what was causing the pain, Sam – who plays Chesney Brown in the ITV soap – rushed his new wife to hospital.
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Posting to Instagram, Briony explained: "Last Sunday, me and Sam sat in bed with a cup of tea binge watching Unbelievable (seriously great show on Netflix) with both doggies under the covers and we discussed having the perfect, cosy Sunday."
Sam took me to hospital where I was given morphine for what we think was kidney stones and that ruined our Sunday dream.
However, their "perfect, cosy Sunday" came to an abrupt end when Briony started to get "crippling pains in my back and belly".
She added: "Long story short: Sam took me to hospital where I was given morphine for what we think was kidney stones and that ruined our Sunday dream."
Briony, who is a yoga teacher, also revealed that she was in so much pain that she "somehow forgot to breathe" when she was taken to hospital.
She said: "Before the meds, the nurse basically turned into a yoga teacher and taught me how to breathe, because somehow despite teaching breath-work about 17 times a week, I somehow forgot how to breathe."
She added: "Nurses rock."
Posting a picture of herself performing a downward dog, Briony – who revealed the episode happened a week ago – wished her followers a "happy" Sunday.
She joked: "I hope you’re all having a happy (kidney stone free) Sunday."
Briony revealed that this Sunday, a week after her hospitalisation, the couple had enjoyed their perfect Sunday.
She said they made cinnamon buns, enjoyed a roast dinner and relaxed on the sofa together.
Briony has previously admitted that she is "so lucky" to have Sam.
When the couple's dog died shortly after their wedding, she revealed: "Sam I are so lucky to have other through good times and bad thank you for the love."
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