The bottom, also referred to as the bum, is the rear of the pelvis. It is composed of large muscles (gluteal muscles), fat and skin. The main structures within it are the rectum and anus, which are the end parts of the gut. The rectum is a long canal that starts from the sigmoid colon of the large intestine. It empties into the anal canal, which forms the last portion of the large intestine. The anal canal then ends in the anal opening, also called the anus. The rectum and the anus play a key role in the passing of stool.
An itchy bottom usually refers to an itch of the gluteal region involving the skin over the bottom or the anus. The rectal canal lacks itch receptors. Therefore, the rectum is not itchy even when painful lesions are present in it. However, lesions in the rectal mucosa may extend down into the anus and skin over the bottom, thereby causing an itchy sensation in these parts.
Read more on itchy rectum.
Causes of an Itchy Bottom
There are many causes of an itchy bottom. It can be broadly divided between the superficial (involving the skin) and the deep (involving the anus and anal canal).
The most common cause of an itchy bottom is also the easiest to prevent. Poor hygiene regarding the anal area, characterized by the accumulation of dried feces, dead skin cells and sweat, can lead to itchy skin around the anus and the adjoining groin area. Regular, gentle cleaning of the anal area would prevent an itchy bottom in many cases.
Dry skin is observed in old people and in those who take regular hot baths. The skin around the anus is sensitive and thin. Dryness of this skin could result in an itchy bottom. Scratching may irritate and damage the skin, further exacerbating the dryness and even making the skin prone to infections which may in turn cause itching.
Foods and drinks such as alcoholic drinks, carbonated beverages, milk products, hot spices, figs, nuts, chocolate, tomatoes, and citrus fruits can cause an itchy bottom as it may irritate the bowel, trigger an allergy or lead to diarrhea which can cause the bottom to become itchy. If a particular food substance is suspected to be associated with an itchy bottom, it should be avoided.
Seborrheic dermatitis refers to skin inflammation caused by a yeast infection. This is observed when the skin become excessively oily due to overproduction of sebum from the sebaceous glands in the skin. Seborrheic dermatitis causes itchy skin in many areas of the body. The skin folds are commonly affected, including the groin region.
Eczema refers to itchy, red skin. Common causes of eczema include diaper irritation (causing diaper rash), allergies to soaps, and irritation due to tight undergarments. Inverse psoriasis is a genetic disease in which smooth, itchy patches of skin occur in regions with skin folds. Anal skin tags are fleshy, dew-drop shaped outgrowths of the skin that arise from the anal mucosa. These skin tags can sometimes be itchy.
Hemorrhoids (or piles) refer to the presence of bloated and tortuous varicose veins in the anal region. Hemorrhoids are classified into two groups: internal and external. Internal hemorrhoids occur inside the anal canal, and are usually not visible from the outside until they become big. These may bleed during the defecation process, and can cause itching and pain when blood flow through them gets blocked because of blood clots.
External hemorrhoids occur in the skin on the anus, and are visible from the outside. These appear as bluish lumps along the periphery of the anal opening. These may cause an itching or a burning sensation. Hemorrhoids are associate with a variety of conditions, including obesity, sedentary work style that involves prolonged periods of sitting, straining during bowel movements, constipation, and pregnancy.
Diarrhea and incontinence
Frequent bowel movements, which are characteristic of diarrheal diseases and bowel incontinence, can lead to an itchy anus. The itch could be a result of friction caused by frequent wiping of the anal region after repeated bowel movements. It my also increase the risk of hemorrhoids which also causes an itchy bottom. Soiling with incontinence can irritate the anus and skin especially if it is not cleaned promptly thereby leading to itching.
Infections and infestations
Fungal infections with the yeast, Candida albicans, is common in skin folds where sweat and dead skin cells accumulate. The groin region is a conducive environment for Candida infection, especially in hot and humid weather. Jock itch (tinea cruris) is a typical manifestation of fungal infection of the groin, and is seen commonly in athletes who are prone to having a moist groin area.
Bacterial infections of the skin around the anus and the groin also result in an itchy bottom. For example, children between the ages of 6 months and 10 years are susceptible to infection with group A beta-hemolytic steptococci that cause red, itchy rash in the groin region (also known as perianal streptococcal dermatitis).
Intestinal parasitic worms may also be a cause of anal itching but not in every person It is more likely to be seen with intestinal pinworm (or threadworm) infestation in children. Theselong parasitic worms come out of the rectum at night to deposit eggs at the anal periphery. This then causes anal itching.
A variety of sexually transmitted diseases (STDs) are responsible for anal itch. These include infections with Chlamydia trachomatosis, Neisseria gonorrhoeae, and Herpes simplex virus. It is more likely to occur with anal intercourse and may lead to inflammation of the rectum an anus, known as proctitis. Other infectious causes includes warts (viral) and pubic lice infestation which may lead to an itchy bottom.
- Inflammatory bowel disease (IBD): Both Crohn’s disease and ulcerative colitis can result in an itchy and painful anal region.
- Anal carcinoma: Anal carcinoma, which is rare before 50 years of age, can cause pain and itchy sensations in the anal region.
Sometimes itching of the rectum is an extension of the a condition that causes an itchy groin. Read more on itchy groin.
Prevention of Itchy Bottom
Medical treatment for an itchy bottom is necessary if it is due to an underlying disease or disorder. However, there are a few simple measures that can assist with preventing an itchy bottom.
- Personal hygiene: Keeping the anal and groin areas clean, especially after bowel movements, goes a long way in preventing an itchy bottom. The anal area should be cleaned gently, and moistened tissues can be used for this purpose. Anal region should also be washed with lukewarm water.
- Avoiding scratching: Scratching the anal area can injure it and make it itchy.
- Avoiding irritant cosmetics: Perfumes, deodorants and powders should not be applied to the anal area. These chemicals can cause an itchy bottom.