Hemorrhoids are perhaps the most common, least talked about problem, as for obvious reasons most people are uneasy talking about their ano-rectal issues. But take solace in the myriad of over the counter hemorrhoid remedies, which while most are ineffectual, at least it tells you that you are not alone.
Hemorrhoids, or at least the hemorrhoidal columns are a normal part of the anatomy of the anus. They are a soft venous plexus that provide a cushion between the mucosa and the more firm sphincter complex. This allows the anus to make a water tight seal, while also being able to stretch to accommodate various sized of stool. We call a hemorrhoidal column a hemorrhoid, when it has become inflamed and/or abnormally enlarged.
Most hemorrhoids can, and should, be managed with a combination of preventative dietary changes, behavioral changes and topical treatments. If you follow these recommendations, you are unlikely to need surgery.
The most important dietary change is switching to a high fiber diet with a goal of approximately 25 grams of fiber daily. This will bulk the stools, and make them easier to evacuate. This requires reading labels, and often supplementing. I recommend using a fiber cereal, and/or Metamucil.
The most important behavioral change is minimizing time on the toilet. Do not read on the toilet. If a bowel movement is not eminent, get up and come back later when it is.
There are numerous topical remedies at the drugstore. I recommend avoiding ointments. Steroid (hydrocortisone) creams can be useful for the treatment of perianal irritation that is often associated with internal hemorrhoids. Most importantly I recommend minimizing, or avoiding toilet paper use, and utilizing flushable wipes, especially those medicated with witch hazel. Tucks and preparation H both make a product like this.

Before discussing the specifics of hemorrhoids, I want to point out that not all anal pain is due to hemorrhoids. Many patients are referred to me for evaluation of hemorrhoids, when what they have is an anal fissure. An anal fissure presents with severe tearing pain with bowel movements. Usually followed by an hour or so of spasm type anal pain. There can be bleeding with BMs and there is often a small protrusion (a sentinel skin tag) in the midline of either the front or the back of the anus. The treatment of an anal fissure is very different from hemorrhoids. It can usually be managed with a topical smooth muscle relaxant (like Nifedipine ointment), but sometime requires surgery (an internal sphincterotomy) if that fails.

Back to Hemorrhoids:

Hemorrhoids are categorized as internal or external. Not surprisingly the external hemorrhoids are easily visible, and most internal hemorrhoids are not. Sometimes the entire hemorrhoid column is involved (both internal and external).

Internal hemorrhoids manifest usually as bleeding and/or irritation. This occurs because the internal hemorrhoid becomes engorged, and ruptures, and thus bleeds, or prolapses through the anus, and breaks the water tight seal, resulting in chronic anal wetness and irritation. Internal hemorrhoids are grades from 1 to 4 depending on their size, degree of prolapse and ease of reducing them. Grade 1 internal hemorrhoids generally do not require surgical treatment, but instead should be managed with diet and behavioral changes (as discussed above). Grades 2 and 3 can usually be treated in the office with rubber band ligation. Grade 4 internal hemorrhoids can sometimes require excision in the operating room. The risks of rubber band ligation are minimal and usually limited to minor bleeding, pain, recurrence and extremely uncommon risk of infection.
External hemorrhoids present as protrusions around the anus. They can be very painful, as when an acute thrombosis occurs, or they can just be chronically irritating, and present as a hygiene problem. An acute thrombosis of an external hemorrhoid is a relatively sudden event. It can be alleviated sometimes by performing an incision and removal of some of the clot from the hemorrhoid as a procedure in the office under local anesthesia. I generally only do this if I see the patient within 3 days of the initial thrombosis, and the hemorrhoid is still very hard and tender. After the hemorrhoid has started to soften and resolve the thrombosis on its own (which it will), cutting it open does not improve much, and may make it feel worse. Most hemorrhoids will resolve on their own, if given time. Surgery for external hemorrhoids is for those that will not resolve or frequently recur. External hemorrhoids, or combined internal/external hemorrhoids cannot be removed in the office, but require general anesthesia for surgery in the operating room. There is no bowel prep required for this surgery, but I recommend using an enema the morning of surgery.
Standard hemorrhoidectomy involves removal of 1 to 3 entire hemorrhoidal columns and closure with absorbable suture. This is the most painful treatment for hemorrhoids, but also the most durable.
Stapled hemorrhoidectomy (aka PPH hemorrhoidectomy) is used when there appears to be circumferential hemorrhoid or mucosal prolapse. This uses a device that removes a ring of rectal mucosa (and staples it back together) above the hemorrhoidal columns, thus interrupting the blood supply and retracting the redundant tissue back into the anus. Yes, some of the staples stay there forever, but it is not something that will affect a metal detector at the airport, or an MRI etc. This procedure tends to be less painful than standard hemorrhoidectomy, but may not retract the protruding external component as much as hoped for.

PPH, Stapled Hemorrhoidectomy, per Ethicon

The operative risks of hemorrhoidectomy include bleeding, infection (rare despite the dirtiness of the area), injury to the sphincters (with continence problems), stenosis due to scarring, urinary retention, constipation and recurrence.

For further discussion of the post-operative course and care please refer to the post-op instructions for these procedures.