Miracles: do they really happen? When something inexplicable occurs, when does it change from being something scientifically baffling to something miraculous? It probably depends on your faith, or lack thereof. Marion Carroll has faith in abundance. She told Oliver Callan – sitting in for Ryan Tubridy – on Wednesday how she went from bed-ridden young mother with a debilitating illness, to symptom-free author of My Miracle Cure.

Marion began feeling unwell after the birth of her first child in the 1970s. As her symptoms progressed, Marion struggled to do things that she used to take for granted. Eventually, she was diagnosed with "probable MS" – Multiple Sclerosis being harder to diagnose before the advent of MRIs. The 1980s were a health nightmare for Marion and she deteriorated to an appalling state:

"In early '87, that's when I lost the power in both of my legs. Then, I had to get the catheter in because I had no control over my bladder and my kidneys were giving trouble. Then I lost power in my right hand and I had only limited power in the left. I was completely blind in the right eye and very little sight in the left eye. My speech was badly affected. The muscles in my throat were affected: to eat, the food had to be cut up very small or liquidised."

On top of all that, Marion had to drink from a plastic cup with a lid and a straw. She needed a collar to support her neck and head. And she had to wear padding because she had no control over her bowels.

"I was just like a baby in a pram. I had to be washed, fed, changed and moved."

An ambulance driver at Athlone hospital, Gerry Glynn, asked Marion one day if she'd like to go to Knock Shrine for a day. She agreed because, she told Oliver, "she'd go anywhere to get away from the four walls". This was even though she would have preferred to go to Lourdes – but they couldn't afford it – because she'd been to Knock twice before, once as a child and a second time, just after she'd been diagnosed:

"It was lashing rain, it was very blustery and it was completely deserted and I thought to myself, 'This has to be the most miserable place on Earth'. And I got into the car, went home, promised I'd never go back. And how wrong I was."

How wrong indeed. In 1989, Marion made the difficult journey by ambulance, strapped into a stretcher. She was placed at the foot of the statue of Her Lady of Knock.

"And I realised something: this is where I wanted to be."

Marion lay looking up at the statue and thought about dying and about her husband Jimmy and their two children, Cora and Anthony. She looked at the statue and spoke:

"I said to her – it wasn't a prayer, Oliver, it was just one woman to another – I just said to her, 'Well you're a mother too. You know how I feel'."

This is how Marion describes how she felt after she received Holy Communion from the Bishop:

"He came in front of the stretcher and he held it up and he blessed me. It was at that time that I got this beautiful feeling, a magnificent feeling."

Afterwards, Marion asked a nurse if she could be unstrapped from her stretcher.

"When she opened the stretcher, my two legs swung out and I stood up straight. I wasn't even a bit stiff after all those years."

Marion had also regained her full speech and the use of her arms. Last September, 30 years after it happened, the Catholic Church declared Marion's experience an "unexplained healing", which is, apparently, what they call miracles in the 21st century.

To hear Marion's full remarkable conversation with Oliver Callan, go here.

My Miracle Cure by Marion Carroll with John Scally is published by Black and White Publishing.

Niall Ó Sioradáin