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IN THE most recent instalment of our series of weird and wonderful facts about your body, we were at the top end of the gastrointestinal tract, talking about the mouth.

This week we are right at the other end, at your anus!

There's more to bums than our fascination with their shape
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There's more to bums than our fascination with their shapeCredit: Getty
Dr Philippa Kaye gets to the bottom of bum facts and myths - from how to wipe and whether you should douche to perineal sunning
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Dr Philippa Kaye gets to the bottom of bum facts and myths - from how to wipe and whether you should douche to perineal sunning

When thinking about bottoms, our focus tends to be on the buttocks.

Fascination with shapely bums might seem like contemporary obsession, but it’s actually been around for centuries. 

But there’s more to derrieres than their shape. 

From how your anus can tell the difference between liquids and solids, to the reason you grow hair on your bum and which direction to wipe in - here are some bizarre facts about bottoms.  

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1. Your anus is a lot cleverer than you probably think

The anus - the opening at the end of your large bowel - is a sphincter, which actually has two parts: the internal and external sphincters.

These have to relax in order for you to open your bowels and do a poo. 

Your anus doesn’t store stool and neither does your rectum, which is the part of bowel just above the anus.

In fact, the rectum is only filled with poo when you need to go to the toilet, and then empties when you do a poo.

The nerves in your rectum and anus communicate with your brain so your anus can tell the difference between a gas, liquid and a solid – after all, you tend to know if you need to fart, do a poo or have diarrhoea!  

Added to this, the high concentration of nerve endings in the anus mean that for many it is an erogenous zone, leading to sexual pleasure.

2. Your anus may be cleaner than you think!

There are literally millions of bacteria in our guts, known as the gut microbiome, and the more we discover about the gut microbiome, the more we realise how important it is!

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So yes, there will be lots of bacteria present in the anus, but there isn’t poo and stool stored in the anus or rectum unless you are constipated.

This means that douching is not required before anal sex, and can be harmful.  

3. Which came first: the mouth or the anus?

Certain body parts develop before others during the development of the embryo. 

For example, nipples form before the Y chromosome kicks into gear during fetal development, which is why men have nipples.

When it comes to the anus, for humans, the mouth does develop before the anus, but that isn’t the case for all animals.

4. Your anus is stretchy

The default position of the anal sphincters is closed and they have to relax and open so that you can do a poo.

But if you look at the anus itself it is crinkled and wrinkled, as it has to open and stretch in order for you to pass stool, which can be of different sizes.

You can get a tear in the anus, called an anal fissure, and this is often related to constipation.

An anal fissure leads to symptoms such as rectal bleeding  and a sharp pain on opening your bowels, often described as sharp like a knife, or being stabbed with a piece of glass.

If you see any rectal bleeding please see your doctor.

Treatment for anal fissures includes laxatives so that you don’t strain at passing stool and to allow your body to heal itself.

5. It isn’t a bunch of grapes!

One of the commonest problems with the anus is haemorrhoids, or piles, which are enlarged blood vessels, like varicose veins, in and around the anus.

They can look like a small bunch of grapes but are actually blood vessels.

Like anal fissures, they are often related to constipation and can present with symptoms such as pain, bleeding and itching.

They can be treated with creams and ointments, suppositories and procedures such as haemorrhoid banding.

However, if you have rectal bleeding please see your GP, don’t assume it is haemorrhoids, as rectal bleeding can be a sign of bowel cancer.

As for old wives tales such as sitting on a radiator can cause piles, there is no evidence to suggest that this is true.

6. Yes, your bottom does sweat

We all sweat and it is true that you can become sweaty around your bottom and anus.

Your buttocks are two areas of skin which continually rub against each other when you walk. 

Sweat helps lubricate this, preventing friction and the skin on your bottom from getting sore.

There are also glands in the anus, which produce secretions to help keep things lubricated when you do a poo.

In animals these secretions help animals identify each other and mark their territory, but although humans don’t do this the glands are still present.

7. Hair has a purpose

Just like pubic hair, hair around your bottom and anus also has a purpose, helping keep the area warm and well lubricated and helps to prevent irritation.

8. Wipe or wash?

Humans have wiped their bottoms with all kinds of things over millennia, from leaves to corn cob husks, from newspaper to toilet paper and simply using your hand and water.

The anus is covered by skin, and, like other areas of skin it can be irritated by soap and cleaning products.

Even wiping excessively and scrubbing at the anus can lead to irritation. 

This leads to itching, which in turn can make you wipe and itch more, leading to an itch-scratch cycle. So wash gently with warm water and a gentle non-fragranced soap.

Make sure to wipe or wash gently after opening your bowels too.

As for the direction of wiping, it doesn’t really matter for adults, as - although the vagina and anus are close together - most adult women are quite accurate when it comes to wiping! 

However, the advice for children is to wipe from the front to the back, as they are generally less thorough with wiping and may leave poo around the genitals, leading to irritation.

9. It doesn’t need sunning!

It was a social media trend recently but perineal sunning, where you expose the anus and perineum (area of skin between the genitals and anus) to the sun is not recommended!

It is quite literally known as the area where the sun doesn’t shine, and exposing it to the sun does not have any proven health benefits. 

Instead, it increases the risk of sunburn and skin cancer, please avoid!

10. Big butts or small, the fascination is centuries old

Moving away from the anus, the fascination with the size and shape of bottoms and buttocks has been around for centuries.

There is an ancient Roman statue called Venus Callipyge, which is thought to be a copy of an Ancient Greek original from centuries before.

The name Venus Callipyge literally means Venus of the beautiful buttocks which are on display on the statue  - showing that we have been looking at bottoms for millennia! 

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11. Having a big bottom may be good for you

Women tend to have larger bottoms than men, as the hormone oestrogen means the body is more likely to accumulate fat in the bottom, hips and thighs as opposed to around the tummy.

This actually may be one of the reasons why women live longer than men, as fat around the tummy and organs is metabolically active and increases the risk of heart attacks and strokes.

The signs of bowel cancer you need to know - remember BOWEL

  1. B:Bleeding

There are several possible causes of bleeding from your bottom, of blood in your poo.

Bright red blood could come from swollen blood vessels, haemorrhoids or piles, in your back passage.

Dark red or black blood could come from your bowel or stomach.

Blood in your stools is one of the key signs of bowel cancer, so it’s important to mention it to your doctor so they can investigate.

2. O: Obvious change in loo habits

It’s important to tell your GP if you have noticed any changes in your bowel habits, that lasts three weeks or longer.

It’s especially important if you have also noticed signs of blood in your poo.

You might notice you need to go to the loo more often, you might have looser stools or feel like you’re not going enough or fully emptying your bowels.

Don’t be embarrassed, your GP will have heard a lot worse! Speak up and get it checked.

3. W: Weight loss

This is less common than the other symptoms, but an important one to be aware of. If you’ve lost weight and don’t really know why, it’s worth mentioning to your GP.

You may not feel like eating, feel sick, bloated and not hungry.

4. E: Extreme tiredness

Bowel cancer that causes bleeding can cause a lack of iron in the body – anaemia. If you develop anaemia you’re likely to feel tired and your skin might look pale.

5. L: Lump or pain

As with lots of other forms of cancer, a lump or pain can be a sign of bowel cancer.

It’s most likely you’ll notice a pain or lump in your stomach or back passage.

See your GP if it doesn’t go away, or if it affects how you eat or sleep

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