feculent

likainen Dirty with faeces or other impurities; turbid; foul, filthy, fetid.
1982, (w), Water Music, Penguin 2006, p. 84:

At this time in history the streets of London were as foul, feculent and disease-ridden as a series of interconnected dunghills, twice as dangerous as a battlefield, and as infrequently maintained as the lower cells of an asylum dungeon.