The anal residual stool is certainly not normal, the anus itself is a very pleated part, it is difficult to wipe clean after the stool, each time after the stool can be cleaned with water. In addition to the artificial situation can be considered is not anal disease, unclean stool, anal residual stool is generally caused by intestinal problems and anal diseases, food into the intestinal tract, if poor digestion, intestinal peristalsis can not function properly will lead to abnormal stool, the output of the stool is too thin, too sticky, too hard will not be clean, the anal opening will be residual stool, anal diseases such as hemorrhoids, anal fistula and Damp heat also causes this phenomenon. Anal diseases can cause anal inflammation, redness and swelling, and perianal abscesses, and if there are internal hemorrhoids, they will secrete mucus when defecating, and the stool will be half dragged outside the anus.