Of the top ten nations that are woefully short of sanitary facilities, India has the dubious honor of being the first.
In an initiative to bring awareness to the need for adequate sanitary facilities, the "big squat" was held worldwide to coincide with the 10th annual World Toilet Day.
Here's a list of the world's worst nations in terms of people lacking access to sanitary facilities, reports The Christian Science Monitor.
1. India: 638 million
The world's second-most populous nation after China, India has the world's largest number of people going outdoors. Nearly 640 million Indians, or 54 percent of the 1.1 billion population lack access to toilets or other sanitation facilities. In some states, the problem was so bad that village women started a slogan: "No toilet, no bride."
2. Indonesia: 58 million
About 58 million Indonesians, 26 percent of its population, don't use toilets. Southern Asia, home to 64 percent of the world's population that still uses the bathroom in the open, has seen the practice decrease the most - from 66 percent in 1990 to 44 percent in 2008.
3. China: 50 million
China has 50 million citizens going in the open. That's only 4 percent of its 1.3 billion population. More than 267 million Chinese have gained access to improved sanitation since 1990, according to the WHO.
As the Los Angeles Times recently found, China's surge in wealth is also causing a spike in toilet purchases. Nearly 19 million toilets are sold in China annually - double the number sold in America.
And six percent of the urban population - compared to 2 percent of the rural population - go in the open, according the WHO's 2010 update on sanitation.
4. Ethiopia: 49 million
Seven in 10 people in Ethiopia's rural areas don't use indoor toilets. The landlocked nation on the Horn of Africa has seen minimal progress over the past two decades in increasing sanitation access, with only 12 percent of the population gaining improved services.
5. Pakistan: 48 million
Of Pakistan's 177 million people, about 48 million go where they please. But Pakistan has seen incredible gains over the past two decades, with 47 million people no longer defecating in the open, according to the WHO's 2010 update on progress on sanitation and drinking water.
However, it saw setbacks recently with the massive flooding that displaced millions of people and worsened already poor sanitation conditions, as the Monitor reported.
6. Nigeria: 33 million
Africa's most populous nation, Nigeria, also has the world's 6th highest number of citizens going to the bathroom outside. Of 151 million people living in Nigeria, 33 million do it in the open. Still, more than 12 million people there have gained access to sanitation facilities over the past two decades.
7. Sudan: 17 million
More than 17 million people, or 41 percent of the population, in the northern African nation of Sudan use the outdoors as their bathrooms.
8. Nepal: 15 million
The Himalayan nation wedged between India and China has low use of sanitation facilities, with some 52 percent of the 29 million population lacking access to indoor plumbing. Still, 31 percent of the population - or 6.8 million people - have seen improved sanitation facilities over the past two decades.
9. Brazil: 13 million
About 13 million Brazilians go to the bathroom in the open, according to the WHO, although this is only about 7 percent of the nation's population of 192 million people.
Over the past two decades, about 80 percent of the population saw an improvement in sanitation facilities, allowing more than 50 million people to gain access to better facilities. Across Latin America and the Caribbean, the percentage of the regional population openly defecating dropped from 17 percent in 1990 to 6 percent in 2008.
10. Niger: 12 million
Four in 5 people in Niger go in the open, according to the World Health Organization (WHO). That's about 12 million people, or 79 percent of the 14.7 million population in the north-central African nation.
It's a slight improvement from the 84 percent of the population who did their business in the open in 1990, according to the WHO's 2010 update on progress on improving sanitation.