[The brown bowel syndrome].

A 37-year-old woman with brown bowel syndrome had yellowish-brown pigment in muscularis propria cells of removed intestine. The pigment occurred here and there in muscularis mucosae, in some arterial walls and in macrophages of submucosa. Its tinctorial characteristics were those of low oxidized lipofuscin. Its probably lysosomal localization was shown by electron microscopy.