Mrs Griswold, not her real name, a school teacher in her early thirties, rushed into the rooms, sweating and groaning in abdominal pain. She knew what was wrong with her. It was constipation, an ailment that plagued her repeatedly, and she knew the solution, an enema. As soon as possible. She was in excruciating pain.  I ascribed her curt manner to her being in significant pain, which she had endured for some time. Pain demands attention.

This was our first meeting, and I proceeded to alleviate her pain, in the manner requested. Immediately. She was correct about her problem, and when more comfortable, we considered the possible causes of the constipation. She continued to display irritation with my line of questioning, but did acquiesce to my request for further tests. Her X-rays confirmed faecal loading and also noted a granular, caseous material present throughout the length her bowel.

She said she could not shed light on what the substance in her bowel could possibly be, but when I suggested she bring a sample in for analysis, she teared up, in the first display of vulnerability.  Then suddenly, the floodgates opened. She spoke quickly, as if to get it all out before she changed her mind.  She had a dark secret she had been hiding for years. It was  a serious problem of addiction, of addiction to chalk. She loved the round-tipped chalk, not the square-tipped chalk. She stocked up on boxes and boxes of chalk. She had boxes in her desk, in her handbag, in her car, next to her bed. She craved it. She dreamed about chalk. She bit, crunched and chewed. No one knew. No one could know. Not her students, her co-workers, her family and especially not her husband. She had no control over her cravings. They consumed her. She was deeply ashamed.

I had never heard of this particular addiction before, but what immediately came to mind, was pica.  I asked her for the make of the round-tipped chalk she bought, and asked her to wait a while, whilst I tried to get to the bottom of the problem. I phoned the manufacturers of the chalk, and discovered that the brand of chalk she spoke of, was made from iron-rich clay. Bingo.

This is the part of my job I love the most. Her palpable relief at discovering that her addiction was simply her body directing her to consume the chalk to give her much-needed iron. How magical is the human body.

In time, we discovered and corrected the cause of the iron-deficiency, and I am very pleased to report that Mrs Griswold no longer has chalk on her shopping list.