Rectal

Horizontal anal fissure. What is the significance of the location of this fissure?

Most (85-90%) fissures occur in the *posterior midline* of the anus. About 10-15% occurring in the *anterior midline*. Fissures located elsewhere (off to the side) should raise suspicion for other diseases.

Good resource

http://fitsweb.uchc.edu/student/selectives/Luzietti/Painful_anus_anorectal_anatomy.htm

How do haemorrhoids present clinically?

Because of the differing nervous innervation above and below this line, the clinical presentation will differ as well. Classic presentation of a patient with haemorrhoids is bleeding (typically with defecation). The bleeding associated with hemorrhoids coats the stool or toilet paper (bright red), whereas the stool is negative for occult blood. - Most cases of haemorrhoids are painless as they are Internal

How are external haemorrhoids treated?

External haemorrhoids typically do not cause many problems. Excision is typically reserved for very large haemorrhoids which interfere with good perianal hygiene. Occasionally, patients may present with severe perianal pain and a lump near the anus following severe constipation or prolonged sitting. Visual or rectal exam may reveal a THROMBOSED external haemorrhoid. A thrombosed external haemorrhoid is one in which blood has pooled and formed a clot. This type of haemorrhoid occurs outside the rectum, around the anal region. It will usually appear as bulging, purple or bluish skin-covered veins, or can be reddish when inflamed. To the touch, it usually feels like a small, hard lump, roughly the size of a pea. With this type of haemorrhoid, most sufferers experience some degree of pain, often quite a lot. A thrombosed external haemorrhoid can cause swelling, itching and/or pain, but it will almost NEVER bleed. The usual Rx is drainage or removal of the clot or the entire haemorrhoid, but ONLY if the condition is acute (<72 hours). Otherwise, expectant management and a high fibre diet is typically all that is needed, as the problem is usually self-limited over 7-10 days.

What are haemorrhoids and where do they occur?

Haemorrhoids are vascular cushions located within the anal canal. They occur in three constant positions: Right Anterior Right Posterior Left Lateral. Internal haemorrhoids - originate ABOVE the dentate line External haemorrhoids - originate BELOW the dentate line - or mixed. Internal haemorrhoids (also known as "piles") are caused by prolapses of rectal mucosa containing the normally dilated veins of the internal *rectal venous plexus*. External hemorrhoids are thromboses in the veins of the external *rectal venous plexus*, and as such are covered by skin.

A young man presents with localised pain & swelling in sacrococcygeal area. What is likely cause and how is it treated?

Pilonidal disease or pilonidal cyst. May be referred to as pilonidal abscess, pilonidal sinus or sacrococcygeal fistula. So an underlying cyst may appear as a sinus tract or fistula; near or in the natal cleft of buttocks. Sx may include: - Pain or swelling above anus or near the tailbone, may come & go. - Opaque yellow purulent or bloody discharge from tailbone area. - Unexpected moisture in tailbone area. - Discomfort sitting on the area, doing sit-ups or bike riding - Excessive sitting may predispose due to increased/constant pressure on coccyx region May result from a blocked hair follicle; with foreign body reaction & infection. - Excessive sweating could contribute to formation of a pilonidal cyst. - Moisture can fill a stretched hair follicle, which helps create a low-oxygen environment that promotes the growth of anaerobic bacteria, often found in pilonidal cysts. - Presence of bacteria and low oxygen levels hamper wound healing & exacerbate a forming pilonidal cyst. Rx Abx, warm compresses, depilatory creams. Severe cases may need excision & drainage: -If acute abscess >> need incision & drainage. If chronic sinus tract >> excision with either: - Closure by secondary intention - Marsupialisation (suturing it open for ongoing drainage)

How are internal haemorrhoids treated?

Rx is based on the severity of symptoms & degree of disease. Asymptomatic disease: - Avoidance of constipation - Bulk-forming agents and/or stool softeners if needed - Sitz baths - With symptomatic disease, rubber-band ligation or infrared coagulation may be tried: A small rubber-band is placed around the base of the haemorrhoid, causing the tissue to die & fall off as a result of lack of blood flow. Likewise, this banding procedure is helpful for second & third degree haemorrhoids as well.

What causes haemorrhoids?

The major precipitator of hemorrhoids is increased rectal pressure - Straining or constipation = commonest cause. Other causes of increased pelvic pressure such as: - Pregnancy - Portal HTN - Excessive diarrhoea can exacerbate their development as well.

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also see https://en.wikipedia.org/wiki/Watershed_area_(medical)

An apparent anal fissure with a small, external, skin tag (sentinel tag) seen at the base of the laceration. The fissure exposes internal sphincter fibres. There are also hypertrophied anal papilla at the level of the dentate line.

careful history and physical exam will usually suggest the diagnosis. Patients often complain of a history of constipation or excessive diarrhea. Pain is common, particularly with defecation and may be disproportionate to the size of the lesion. If bleeding is present, it is usually bright red, and in fact, is the most common cause of bright red blood per rectum (BRBPR) at any age. The diagnosis is made by inspecting the anal region. Gentle retraction of the buttocks will reveal the tear. Having the patient bear down will aid in seeing a fissure if it is present. In cases where a fissure cannot by seen, a digital exam should be done to rule out other pathology. Likewise, if pain limits the diagnosis, an examination under anesthesia would be appropriate. If the fissure is chronic, a small, external, skin tag (sentinel tag) may be identified at the base of the laceration. Additionally, if the fissure exposes internal sphincter fibers and there are hypertrophied anal papilla at the level of the dentate line, then this triad of features is generally considered pathognomonic for chronic fissures.