If you are using toys, apply the same rules as in other types of ass play – start small and build up slowly and gently, stopping if things hurt. Forcing things could risk tearing sphincter muscles. Use lots of lube. If you are playing for a while, reapply lube when things get dry. If you are using really big toys, make sure that they can bend, as your colon turns a corner about eight inches in from your anus. Really thick toys can damage muscles and lead to problems with bowel control later in life. Dildos and toys with flared bases are safer as there is less risk that they will end up stuck inside you. Don’t be afraid to go to the hospital if you do get anything stuck inside. Avoid using bottles or anything breakable.

Sharing sex toys can pass body fluids, including HIV-infected blood, from one person to another. Cover your toys with condoms and change these if the toy is going into a different butt, or clean them with one part bleach to ten parts soapy water.

What is a Dildo?
There are a lot of different ideas out there about what dildos really are. There is general agreement that a non-vibrating device, resembling a penis in shape, size, and overall appearance, is a dildo. Some people include vibrating devices in that definition. Some might exclude penis prosthetic aids, also sometimes called "extensions." Some authorities include devices designed for anal penetration (butt plugs), while others do not.

Evolution of Dildos
Early dildos were made of stone, wood, leather, or pottery. Of these, leather dildos with a fairly solid filler of cotton rag remain popular with some people.

Rubber dildos, usually incorporating a steel spring for stiffness, became available in the 1940s. This of course wasn't the most satisfying or safe arrangement when the rubber finally cracked and came apart causing potential for serious injury from cuts from the spring. Later, PVC dildos with softer PVC filler became popular. Most of the inexpensive dildos sold today are made this way.

Chrome-plated steel dildos have been made, and have a small following, especially in BDSM circles. They are not particularly comfortable because they do not flex. In the 1990s, silicone rubber dildos became more popular, a trend that has continued as the price has come down. These are easier to keep clean and do not have the characteristic plastic aroma of PVC. They were expensive when introduced but are now reasonably priced, making them an excellent choice for the first-time user. More recently, dildos made of borosilicate glass (Pyrex) have come on the market. They are expensive, and inflexible, but have a following. Other materials have been used as well.

In addition to anal penetration, dildos have fetishistic value as well, and some guys use them in other ways, running them over the skin during foreplay for example. If of appropriate sizes, they can be used for oral penetration or a sort of artificial fellatio.

Safety and Health
Some larger dildos are intended for visual appeal only and should not be used for penetration.

Keep Your Dildo to Yourself
Dildos can transmit disease between users in the same way as other forms of sexual contact, and should not be shared among users where this is a concern. This is particularly true for dildos made of porous or micro-porous materials, such as most soft synthetics. On the other hand, smooth stainless steel or Pyrex dildos are easier to clean, non-porous, and can be more easily sanitized, either chemically or by boiling. This is not meant to say that more than one person should use any unprotected dildo without being sanitized. An effective remedy is to use a fresh condom on the dildo.

While steel or metal dildos may be easier to sanitize, softer materials better align with the curves in your rectum so you don't damage protective mucosal linings… remember the linings are there naturally as a barrier against HIV and STDs.

"It’s Stuck, It’s Stuck!"
Dildos without a flanged base or other mechanism to control the depth of insertion should not be used anally, because they can be difficult to retrieve without medical assistance. If a dildo or other sex toy does go up inside you beyond reach, squat and bear down slightly: the object will probably come down on its own. If it doesn't appear within an hour seek medical attention from an emergency room. Take a friend; even though the ER has seen it all before, there’s something to having a little support in the face of the inevitable snickering nurse.

Know Thy Self
Crucial to pleasure with dildos is having an understanding of the curves and byways of the rectum. Most of the lower part of the rectum runs toward the belly button, however about three inches in, it takes a curve in the opposite direction, toward your back. If you're in the right position and relaxed, the curve straightens out somewhat to allow free passage. If you ignore your curvature, the dildo you are trying to put up yourself will run smack into the wall. Ouch!

Some of the discomfort associated with dildo use comes from trying to force your way by this wall, rather than readjusting to get it in more easily. With enough forcing, you can get a tear, better known as a fissure, or a deeply unpleasant pain. It's much better to figure out how to line things up so they can move in more smoothly.

The great thing about dildo use is that you control the pace. Go as slowly as you need to, try to breathe deeply and easily, and dispense with the idea that you have to get it "all the way in." If you encounter resistance at the first curve, try pulling out a little, adjusting the angle, and moving in again. When you find an angle that works, make a mental note of it for future use. Some men use dildos with suction cup bases that stick to the wall, finding it hotter and easier to move their bodies into the dildo than the other way around, leaving their hands free for better masturbation.

As you experience a new sensation, try to figure out if it is uncomfortable or simply unfamiliar. If you are unable to get it in at all, find it too painful, or feel worried that you are going to inadvertently move your bowels, try relaxing techniques and whether moving in or out, move slowly.

Relax and Enjoy
Often, as you insert something longer than a finger into your ass, your internal sphincter tightens just as it would if some fecal matter or gas were tickling it from above. The result is the familiar feeling of having to move your bowels. Feelings, as the old self-help saying goes, are not facts.

Breathing through the muscle's reflexive tightening can help loosen it, as can the realization that you are not really about to move your bowels and so you don't need to be as tense. From light stroking of the external anal area to impaling yourself on a life-size dildo, there's pleasure there somewhere. Take the time!

Dildo Buffet
There are double-ended dildos of various shapes, making for twice the fun when used with a partner. Then there are double dildos, with different-sized shafts pointing in the same direction. There are even inflatable dildos! Dildos with balls, a flared base, or a suction cup make for easier control and less fear of losing it inside your rectum.

Dildo Shopping Tips
Deciding on a dildo comes down to three things: shape, material, and color. You want something that looks and feels good. Most dildos are made of rubber. There are different types of rubber with their own unique look and feel. The least expensive dildos are made of a plain rubber. These toys are great for experimenting and can be just what you're looking for. Jelly rubber is another kind of rubber that is still affordable, slightly lighter, and comes in far more interesting colors.

Silicone rubber is the highest quality rubber used for making dildos. It retains body heat more than plain rubber, it's more resilient, non-porous, and can be boiled in water to sterilize. Additionally, silicone conducts vibrations really nicely - just place a vibrator against the base for great effect. They are available in a greater range of shapes and colors, and are all hand-made by small manufacturers.

Hard plastic dildos have a look and feel all their own. The benefits are the ease with which you can reach certain spots (since the toy doesn't bend when inserted), as well as easy cleaning. Some folks find these toys too hard, or say that they only play with them for short periods of time. For beginners, the rule is to start small; going big will probably only send you back to the store next week, and they're neither cheap nor returnable.

Information from the book Men Like Us by Daniel Wolfe and the following websites: