In recent days the signs prohibiting defecation have appeared in the hamlet of Lastres in the Lugo province of Galicia.
The signs have been posted by residents who complain that pilgrims often "leave deposits" on their way through the village which lies on the Camino de Santiago, sometimes in the street right in front of their homes.
The notices appear next to other signs asking people not to drop litter but none of the residents will admit to having been the one to stick them up.
"Lastres is a tiny village with very few residents," a hotel owner from the next town along the route told The Local.
"But it's a common problem. People living in places on the Camino de Santiago understandably do get fed up if pilgrims don't behave respectfully," he said.
Last year more than 240,000 people traveled the camino to reach the shrine of St James - a pilgrimage that dates back to the ninth century - the majority on foot but others choose to do it by bicycle, or on horseback.
Pilgrims tend to stay in hostels and religious lodgings such as convents and monasteries along the route and use local facilities when they are available.
"From time to time we have had complaints from individual landowners about pilgrims going to the loo on their property," admitted Maite Moreno from the Federation of Friends of the Camino de Santiago, the organization that oversees the pilgrimage paths.
"But this is the first time I have heard of a community doing something to try and stop it," she told The Local.
"The problem is that people go when they need to go. We would encourage pilgrims to be thoughtful about this but we don't issue them with rules or anything," she said.
"There is no official guide to being a good pilgrim but we expect people to use their common sense, be polite and of course pick up after themselves," she added.
Some in the village of Lastres say the signage is already showing benefits. "People definitely notice them, they stop and take pictures," Jose Ramon, a resident of Lastres told local Galician newspaper El Progreso.