BANGKOK — The BTS Skytrain will not post signs indicating where toilets are as the number of users could become overwhelming, the BTS chairman of Advisory Board said Saturday.

Anat Arbhabhirama’s remark during a phone interview came a day after a man defecated on the seat of a Skytrain carriage near BTS Phra Khanong and fled, leaving passengers to deal with the odor.

“If you really need to be relieved ask security guards, they will lead you [to use the toilet] every time, but you must be escorted due to security concerns. But if a sign is posted there will be many people using it and it won’t be enough,” Anat said Saturday. “It’s meant to be used by staff.”

Asked if the BTS has plans to build toilets meant for its near 700,000 daily passengers, Anat said the space for it is inadequate, adding that Japan and Singapore’s skytrains have no purpose-built passenger toilets either.

“There’s no space and the stations are connected to many buildings,” said Anat, suggesting passenger could relieve themselves in those.

On Friday morning, a man, described by BTS spokeswoman Kanittha Totrakul as “an uncle” could not control his bowels and left some excrement on a train seat before asking BTS guards to clean himself up in the staff washroom.

Facebook user Nidtayaporn Songsri captured a picture of an empty seat with what appeared to be human excrement and other passengers covering their noses. It led to a social media debate as to why there are no toilets for commuters.

“It’s a sunny Friday morning but I pity that we have to face such things #BTSBrownBomber The bro can’t just shit and flee because people suffer,” Nidtayaporn wrote.

“BTS drama continues. It’s so difficult to gain access to toilets. You have to ask on a personal basis,” Chulalongkorn University political scientist Pitch Pongsawat wrote Friday on Facebook.

Pitch said he wondered how others near the excrement managed to continue their commute.