I had thought I had heard it all. I really believed there was little more to know about the human condition, certainly nothing that would shock me to the core. But I was wrong.

Last month, I visited the Hamlin Fistula Hospital in the Ethiopian capital Addis Ababa and learned about what has to be, probably the most outrageous indignity nature imposes on women.

I discovered the truly awful obstetric fistula and was reminded of those lines from Pádraig Pearse's poem The Mother. "Lord, thou art hard on mothers: We suffer in their coming and their going."

There can be no doubt that, where Mother Nature is concerned, the fairer sex gets the rawest deal. And none more so than when a fistula occurs.

Let me explain. . . and this is not for delicate sensibilities. A fistula usually happens during a first pregnancy and frequently because the girl is not physically mature enough to have a child. Though in labour for days, she remains unable to deliver the baby, which dies and is expelled from the womb.

During this prolonged labour a fistula develops when the blood supply to the tissues of the vagina and bladder (and/or rectum) is cut off causing tissue to die and leaving a hole through which urine and/or faeces pass uncontrollably. It does not heal and leaves the girl incontinent for life, sometimes doubly so.

As a consequence she in usually abandoned by her husband and becomes isolated from her community, or isolates herself from the community, such is the offensive odour she gives off due to incontinence. Fistulas are very rare in the developed world but remain common in poorer countries.

In Addis Ababa, Drs Reg and Catherine Hamlin, both gynaecologists from Australia, who arrived in the city 55 years ago, set up the Hamlin Fistula hospital where they've successfully treated more than 40,000 women to date.

Reg Hamlin died in 1993 but his 91-year-old wife Catherine is still there. It is not possible to adequately describe what their life's work has meant for the women to whom they've returned the gift of a normal life. Or the hope it has allowed for the estimated two million women in Asia and sub-Saharan Africa who are said to suffer from the condition. Fistula, from the Latin fistula, meaning a pipe or ulcer. Details at hamlinfistula.org/