A fan blows a gentle breeze across a women's ward in a hospital in Dar es Salaam in Tanzania. It comes as a relief to 25-year-old Rukia Pendeza who lies in a bed recovering from an operation to repair an obstetric fistula. Obstetric fistula occurs following a protracted and difficult childbirth and leaves women unable to control their urine and faeces. It is a gynaecological problem which affects the poorest of women in developing countries and it also appears to be on the increase in Tanzania.