The odor returned from the window toilet may be the odor caused by the blockage of the toilet and squatting toilet. Or something that smells like the window facing the garbage dump.
Most of the time, opening the window to ventilate and remove the smell in the bathroom is our first choice, but sometimes we don't know why opening the window not only doesn't ventilate, but even makes the smell in the bathroom heavier.
This may happen because some toilets or squatting toilets in the toilet are blocked, and the toilet or squatting toilet has become the source of smell. Even opening windows for ventilation has little effect, and even the smell near the toilet and squatting toilet will be blown away to the whole room.
Or maybe the window in the bathroom is facing something that will produce smell, such as a garbage dump. In this way, the more you open the window, the more the wind will bring the bad smell outside into the bathroom.