There are several theories, including inadequate intake of fiber, prolonged sitting on the toilet, and chronic straining during a bowel movement. None of these theories has strong experimental support. Pregnancy is a clear cause of enlarged hemorrhoids though, again, the reason is not clear.
As the anal cushion of an internal hemorrhoid enlarges, it bulges into the anal canal, loses its normal anchoring, and protrude from the anus as a prolapsing internal hemorrhoid. The hemorrhoid is exposed to the trauma of passing hard stool causing bleeding and sometimes pain. The rectal lining that has been pulled down can secrete mucus. The presence of stool and constant moisture can lead to anal itchiness (pruritus ani); though itchiness is not a common symptom of hemorrhoids.
Hemorrhoids that bleed but do not prolapse.
Hemorrhoids that prolapse and retract on their own (with or without bleeding).
Hemorrhoids that prolapse but must be pushed back in by a finger.
Hemorrhoids that prolapse and cannot be pushed back in.
In general, the symptoms of external hemorrhoids are different to the symptoms of internal hemorrhoids. External hemorrhoids can be felt as bulges at the anus, but they usually cause few of the symptoms that are typical of internal hemorrhoids. External hemorrhoids can cause problems, however, when blood clots inside them. This is referred to as a perianal hematoma. Thrombosis of an external hemorrhoid causes an anal lump that is very painful (because the area is supplied by somatic nerves) and may require incision and drainage.
This small procedure can effect immediate symptom relief. The thrombosed hemorrhoid may heal with scarring and leave a tagof skin protruding from the anus. Occasionally, the tag is large, which can make anal hygiene difficult or irritate the anus. In these cases, surgical excision might be necessary.
By the history of symptoms, we can suspect that hemorrhoids are present. The diagnosis of an internal hemorrhoid is easy if the hemorrhoid protrudes from the anus. Although a rectal examination with a gloved finger may uncover an internal hemorrhoid high in the anal canal, a more thorough examination for internal hemorrhoids is done visually using an proctoscope. As the proctoscope is withdrawn, the area of the internal hemorrhoids is well seen. Straining by the patient may make the hemorrhoids more prominent.
Rectal mucosal prolapse can also mimic internal hemorrhoids. External hemorrhoids appear as a lump and/or dark area surrounding the anus. If the lump is tender, it suggests that the hemorrhoid is thrombosed.
Although we should try our best to identify the hemorrhoids, it is perhaps more important to exclude other causes of hemorrhoid-like symptoms that require different treatment. These other causes - anal fissures, fistulae, perianal skin diseases, infections, and tumors - can be diagnosed on the basis of a careful examination of the anus and anal canal. Any lump needs to be carefully followed, however, and should not be assumed to be a hemorrhoid since there are rare cancers of the perianal area that may masquerade as external hemorrhoids.
Whether or not hemorrhoids are found, if there has been bleeding, the colon above the rectum needs to be examined to exclude important causes of bleeding other than hemorrhoids. Other serious causes include colorectal cancer or polyps or inflammatory bowel disease. This examination can be done by either flexible sigmoidoscopy or colonoscopy.
Rubber band ligation
Surgical removal of hemorrhoids (hemorrhoidectomy) usually is reserved for patients with third or fourth-degree hemorrhoids. During hemorrhoidectomy, the internal hemorrhoids and external hemorrhoids are excised using diathermy. The wounds left by the removal are left open. This is performed as a daycase procedure. Post surgical pain is the major problem with hemorrhoidectomy. The addition of NSAIDs enhances the relief of pain. Delayed hemorrhage 7 to 14 days after surgery occurs in 1-2% of patients. Wound infections are uncommon after hemorrhoid surgery. Abscess occurs in less than 1% of cases.
However, patients commonly complain of discharge postoperatively and this is expected as the wounds are left open. If the wounds look clean, they do not necessarily need antibiotics. Patients should be advised to keep the area clean and dry and avoid topical applications of ointments or powder.
Stapled hemorrhoidectomy is a technique developed in the early 1990s but is a misnomer since the surgery does not remove the hemorrhoids but, rather, the abnormally lax and expanded hemorrhoidal supporting tissue. The arterial blood vessels that travel within the expanded hemorrhoidal tissue are cut, thereby reducing the blood flow to the hemorrhoidal vessels and reducing the size of the hemorrhoids.During the healing of the cut tissues around the staples, scar tissue forms, and this scar tissue anchors the hemorrhoidal cushions back to their normal position higher in the anal canal thus effectively an anopexy is performed.