Piles / Fissure / Fistula
Piles also called hemorrhoids, are swollen veins in your anus and lower rectum, similar to varicose veins. Piles can develop inside the rectum (internal hemorrhoids) or under the skin around the anus (external hemorrhoids). Nearly three out of four adults will have piles from time to time. Piles have a number of causes, but often the cause is unknown. Fortunately, effective options are available to treat piles. Many people get relief with home treatments and lifestyle changes.

External Piles

These are under the skin around your anus. Signs and symptoms might include: Itching or irritation in your anal region| Pain or discomfort | Swelling around your anus | Bleeding

Internal Piles

Internal hemorrhoids lie inside the rectum. You usually can’t see or feel them, and they rarely cause discomfort. But straining or irritation when passing stool can cause: Painless bleeding during bowel movements. You might notice small amounts of bright red blood on your toilet tissue or in the toilet. | A hemorrhoid to push through the anal opening (prolapsed or protruding hemorrhoid), resulting in pain and irritation.

Thrombosed Piles

If blood pools in an external hemorrhoid and forms a clot (thrombus), it can result in: Severe pain | Swelling | Inflammation | A hard lump near your anus

Fistula
An anal fistula is a small tunnel that connects an abscess, an infected cavity in the anus, to an opening on the skin around the anus.

The anus is the external opening through which feces are expelled from the body. Just inside the anus are a number of small glands that make mucus. Occasionally, these glands get clogged and can become infected, leading to an abscess. About half of these abscesses may develop into a fistula.

The leading causes of an anal fistula are clogged anal glands and anal abscesses. Other, much less common, conditions that can cause an anal fistula include: Crohn’s disease (an inflammatory disease of the intestine), Radiation (treatment for cancer), Trauma, Sexually transmitted diseases, Tuberculosis, Diverticulitis (a disease in which small pouches form in the large intestine and become inflamed), Cancer

Fissure:
An anal fissure is a tear in the lining of the anus or anal canal (the opening through which stool passes out of the body). The fissure can be painful and may bleed. Anal fissures can occur in anyone at any age. The chance of having an anal fissure decreases as people get older. People who have had fissures in the past are more likely to have them in the future. Anal fissures can be caused by trauma to the anus and anal canal. The trauma can be caused by one or more of the following: Chronic (long-term) constipation, Straining to have a bowel movement, especially if the stool is large, hard and/or dry, Prolonged diarrhea, Anal sex, anal stretching, Insertion of foreign objects into the anus.

Causes other than trauma include:

Longstanding poor bowel habits, Overly tight or spastic anal sphincter muscles (muscles that control the closing of the anus), Scarring in the anorectal area, An underlying medical problem, such as Crohn’s disease and ulcerative colitis (types of inflammatory bowel disease); anal cancer; leukemia; infectious diseases (such as tuberculosis); and sexually transmitted diseases (such as syphilis, gonorrhea, Chlamydia, chancroid, HIV), Decreased blood flow to the anorectal area.