The whole world knows how effectively a glass of Oral Rehydration Solution (ORS) can help replace the fluids lost during diarrhoea . The solution is that popular. But what's not so famous is the man who has been instrumental for discovering the pathbreaking solution - Dilip Mahalanabis.Leave alone the whole world, even the people in his locality, who must have a packet of ORS in their houses quite like every other Indian, are not aware that the solution is the brainchild of the soft-spoken man who lives next door. And for the rickshaw pullers, he is just daktar babu (doctor).For almost past two decades (since his retirement in 1995 from the International Centre for Diarrhoeal Disease Research, Bangladesh), a two-storey CF-198 building located on Kolkata's posh eastern fringes Salt Lake has been the home for this octogenarian Indian biologist - the man who saved millions with his crucial oral solution.ORS was perhaps the most significant medical invention of the 20th century. It did not come about from some sophisticated molecular biology experiment but from the urgent need to manage severe cholera outbreak spreading among innocent victims at the time Bangladesh War in the early '70s.It was no one else but Mahalanabis who responded to the need of the hour, fought against all odds to establish the life-saving electrolytic solution and made its presence felt in the global medical fraternity as an easily-manageable alternative to Intravenous Rehydration Therapy (IRT).Recalling the days he had mostly spent in labs, hectic workshops and field trials in West Bengal's border town Bongaon during the summer of 1971, Mahalanabis said: "The process was not at all easy as it deviated from the traditional methods of treatment for diarrhoea and cholera. I had to spent years working on the project, making experts and scientists believe that it can do wonders on patients suffering from intestinal diseases."The biologist added that during the Bangladesh liberation war thousands of homeless people had migrated to numerous refugee camps located on Indian side of the border. They did not have any access to drinking water and sanitation and were suffering from severe outbreak of cholera. Everyone, especially children, was dying of diarrhoea and cholera."It was urgent to provide them with correct proportions of rehydration ingredients. And I decided to treat people with a simple solution of sugar and salt called ORS - a simple solution that turned out to be a miraculous tool to bring down death rates in the camps," said the publicity-shy biologist who now runs an independent research body in the fields of vaccinations.After its mass application in the refugee camps, the World Health Organisation (WHO) took up the project across 105 countries and accredited the use of ORS globally. Later, it was used in hundreds of refugee camps by the United Nations (UN).The initiative has successfully reduced total diarrhoea deaths. According to the reports available, over 1.2 million deaths were registered because of diarrhoea globally in the '90s and the figure dropped down to less than a million in 2010.A modest Mahalanabis smilingly dedicated the global acceptance of ORS to his teacher Dhiman Barua who was also associated with WHO and gave a significant push to the noble initiative.