[3] I found it more convenient to use the words mucus channel, mucus fistula, etc., in preference to sinus, as they better convey my ideas to the average reader. If a recto-anal mucus channel, under one or more layers of the mucous membrane, becomes constricted or obstructed (they usually do), its epithelial wall will become sacculated, and then we have a rectal mucous sac, or an ano-rectal mucous sac, or an ano-muco-cutaneous sac, all of which may be present in the same case. The inflammatory exudation called serum distends and destroys fatty tissue, which makes space for its lodgment under the tissue that imprisons it, and at the same time there occurs more or less proliferation of the cells of the tissue involved in the severe inflammation. The internal sphincter muscle, by its contraction, aids in the undue retention of the mucus and blood above it, hence the so-called pile-bearing region--that is, the sacculated mucosa region. The serous exudation meets with obstruction along the anal canal and the mucosa is sacculated. When the integument around the anus offers obstruction to the flow of serum and blood, we find that muco-cutaneous sacs are formed around the anus. If the exudation occurs in the areolar space under the ano-rectal mucosa, it readily passes down into the areolar space under the integument around the anus, and thence to parts deep, devious, and far away, as described in Chapter III. Channels, reservoirs, sacs, that would hold from one to eight or more ounces of fluid, no longer excite my wonder and amazement at the extensive and serious pathological condition of which they are exhibits, a pathological condition that occasions symptoms often diagnosed as sciatica, rheumatism, myalgia, caries of the coccyx, coxitis, prostatitis, pruritus ani, scroti, and vulvæ, auto-intoxication, anemia, invalidism, etc. Inasmuch as we have learned the cause of sacculated mucosa at the lower end of the rectum and over the anal canal and of the integument around it, we had better in future omit the following designations and distinctions, which are merely a ridiculous display of sciolism. Surely we can do without them, and ought to do so for the sake of truth and simplicity. With a sigh of relief let us in future ignore: Safety-valve piles, organized piles, itching piles, blind piles, bleeding piles, moon piles, cutaneous piles, thrombotic piles, external and internal pile tumors, venous piles, ulcerated piles, capillary piles, mixed hemorrhoids, arterial hemorrhoids, white hemorrhoids, acute hemorrhoids, chestnut hemorrhoids, chronic hemorrhoids, inflammatory hemorrhoids, hypertrophic hemorrhoids, atrophic hemorrhoids, Egyptian piles, Philistine itching hemorrhoids, etc.