Archive for the ‘Tecnociencia’ Category


26 octubre 2009

Eugenio Lucas Velásquez - La lavativa

HOW TO GIVE YOURLSEF AN ENEMA by Catherine Cavanaugh, R.N.

An enema is a safe, effective, and natural way to cleanse the bowel. It more closely approximates a natural movement than laxatives or suppositories and is much more gentle on the system. Only the last 24 to 36 inches of the digestive tract are involved, as compared to over 30 feet as is the case with laxatives. When you are constipated and resort to a laxative you never really know where you will be and what you will be doing when your laxative decides to work. With an enema you time your movement to your convenience.

Nevertheless, in many people, just the word “enema” brings to mind unpleasant memories of the discomfort of past or childhood enemas. In fact, an enema, properly administered, and taking care to observe some fundamental principles, can be almost without discomfort.


  1. An enema bag or can. You can obtain this in any pharmacy. A combination hot water bottle/fountain syringe is the most convenient if you will be giving the enema to yourself. This is because you can set the bag down after it is filled without spilling the solution. A stainless steel irrigation can is more expensive, but easier to use when administering an enema to someone else, and also easier to prepare and clean up afterward. These are available from surgical supply stores. If you travel frequently you may want to consider a folding enema bag travel kit. Also available in some pharmacies, and most surgical supply stores, are inexpensive hospital type disposable enema bag units. In the hospital they are used once and discarded for sanitary reasons, but you can use them several dozen times at home before they wear out.
  2. A Davol colon tube. This is a flexible red rubber tube, 18-30 inches long that attaches to the hard plastic enema tip. It provides more safety and comfort than the standard attachment. These are available from medical supply stores and come in different sizes denoted by their French number. This number designates the interior diameter of the tube, the higher numbers indicating a larger diameter or the ability to pass more solution in a given time. Fr.#26 to Fr.#30 are standard sizes for the average adult, while Fr.#18 is used for young children, and intermediate numbers for ages in between.
  3. Castile enema soap. This is very mild soap used in the hospital for cleansing enema solutions. It is gentle enough to use on infants, but effective enough to relieve the most stubborn case of constipation. It is in liquid form and comes in a box of 50 single use packets. It is inexpensive and your pharmacist can order it for you, or you can find it stocked in many surgical supply stores. Soapsuds enemas are only recommended in cases of constipation.
  4. K-Y Jelly, vaseline, or cold cream for a lubricant. This is used to make insertion of the rectal tube easier and more comfortable.
  5. Something to hang the bag if self-administered. The enema bag should be suspended no more than 18-24 inches above the level of the rectum. The best place to give yourself an enema is on the bed, or in the bathroom either lying on a rug or in the bathtub. The bed is the more comfortable alternative. If there is no hook or something to suspend the bag from near the bed, put a nail or some sort of a hanger into the wall, so the enema bag can be hung by a strong cord so that it is about 18 inches above your rectum when lying on your side. If you prefer the tub, a string looped over the shower curtain pole or shower head can be used to hang the bag. Some enema bags come with an “S” hook that can be hung on the end of the cord. You can also make one by bending a piece of a coat hanger into an “S” shape.
  6. A pad or heavy bath towel. This is placed underneath the buttocks during the enema. On the bed or bathroom rug it helps to absorb any leakage, and in the tub makes it more comfortable than contacting the bare tub surface directly.


For best results, and your own comfort, the enema should be taken while lying down.

  • If you will be giving the enema to yourself the first thing you should do is set up the area for the procedure. Make sure the hook is suspended at the proper height (18-24 inches above the rectum). Then place a pad or bath towel where you will be lying down. Slide the shutoff clamp to a point on the tubing where you will be able easily reach it while in position. Check this out ahead of time by hanging the empty bag and assuming the position, just to be sure.
  • Prepare the solution. The water temperature should be slightly above body temperature, about 105 degrees F. at preparation time.For a soapsuds enema, if you have a combination hot water bottle and syringe, or an enema can, empty the contents of one castile soap packet into the bag or can, and fill with warm water. If you have a fountain syringe, or hospital type disposable enema bag, then first you should fill the bag one-third full of water before pouring in the castile soap. Then resume, filling the bag with desired amount of water. This prevents the soap solution from running out the enema tubing when the air is expelled. For a combination syringe, after attaching the tubing shake the bag to mix the solution thoroughly. For an enema can, stir the solution with some sort of a stirrer. If castile soap is not available, mix a bar of any mild toilet soap (IVORY, DOVE, etc.) in a pitcher of warm water until the water becomes milky, and then fill the bag or can. CAUTION: Do not use liquid dishwashing detergent such as IVORY liquid or any other in an enema since these soaps are very irritating to the bowel and their use has reportedly resulted in cases of soap induced colitis.
  • For a salt solution enema, mix 1 teaspoon of table salt for each pint of solution, or four teaspoons for two quarts.
  • For a tapwater enema merely fill the bag with warm water. If you have a problem with water purity in your area then warmed distilled or bottled water is preferred.
  • Lubricate the rectal nozzle with vaseline, K-Y jelly, or cold cream.
  • Open the shutoff for a moment and allow enough solution to flow to expel the air from the enema tubing. This helps to reduce cramping.
  • Lubricate your anal area with a generous amount of K-Y Jelly, or cold cream. Work your index finger up into the rectum lubricating the entire interior area where you can reach. This serves two purposes: 1. It makes it easier to insert the rectal tube, and 2. It helps protect the sensitive skin around the rectal area from being irritated by the harsh wastes when the enema is expelled. Wipe your finger with a tissue.
  • Hang the enema bag on the hook.
  • Lie down in position. On the bed this should be on the left side with the left leg straight and the right knee flexed (Sim’s position). Your left arm should be behind your back and if the shutoff is properly positioned you will be able to control it with your left hand. Your right hand will comfortably rest under your pillow. On the bathroom floor or in the tub, lie on your back with both legs drawn up, knees bent. Make sure you can easily reach the shutoff valve. Put a pillow under your head.If someone else is giving you the enema you may find it more comfortable to assume the knee-chest position. To accomplish this, get on your hands and knees and then put one or two pillows underneath your chest, and lean forward on them. Turn your face sideways and rest it on another pillow, and snuggle both arms underneath. This particular position is an especially comfortable one to have an enema during pregnancy, but if you attempt it on your own the rectal tube tends to slip out and it is difficult to work the shutoff. If you do this on the bathroom floor rather than the bed, make sure your knees are cushioned by a pillow or a pad, or the pressure on them might cause knee damage.
  • Gently insert the rectal tube 3 to 4 inches into the rectum. Rotate or twist the tube back and forth to make for easier insertion.
  • Open the shutoff valve and allow the solution to flow. At the first indication of discomfort stop and wait a few moments. Then release the shutoff and allow the enema to resume. Feel free to interrupt the flow as frequently as is necessary to assist in minimizing the discomfort. Taking slow deep breaths will help, and if you feel cramping at any point “pant like a dog” with shallow quick breathing. As the enema progresses a feeling of fullness develops. This is normal, and discomfort can be minimized by insuring that not too much solution is introduced too quickly. Take your time.
  • When the bag is empty clamp off the shutoff and slowly remove the rectal tube. Remain in position and retain the solution for a while. For a maintenance enema a few minutes are sufficient, but if you are constipated try to hold it in for 5 to 15 minutes.
  • Go to the toilet and expell the enema. An enema seldom comes out in a single movement so stay near the toilet for one half to one hour. After evacuating, most people find it comfortable to lie on the bed in a prone position to rest for a while.
  • A soapsuds enema should always be followed by a clear water rinse to insure that any soap solution residue is washed out of the colon. This minimizes the possibility of any irritation. Follow the instructions above but this time just use tapwater and try to take an entire bagful. This combination of a soapsuds enema followed by a clear rinse is the preferred treatment for cases of constipation.
  • Clean the equipment thoroughly. Remove any trace of lubricant from the rectal tubing with tissue, and wash with warm soapy water. Rinse out the bag or can, because intestinal pressure can cause reflux (a backing up of solution and colon waste into the bag or can). Then refill the bag or can part way, reattach the tubing if disconnected, and allow the water to flow into the sink, rinsing out the tubing.
  • Hang up to dry. An enema bag takes several days to thoroughly dry out, and should never be put away while even slightly wet.


There are three primary reasons that cause an enema to be a more uncomfortable procedure than it has to be:

  1. Wrong position.- Many people are under the misconception that an enema can be successfully taken while seated upon the toilet. In some cases this may produce minimum results that may be construed as success, but in fact, gravity works against the enema and inhibits the solution from reaching the upper parts of the colon, and causes unnecessary discomfort as the solution pools in the lower part of the, bowel causing it to uncomfortably expand. An enema taken while seated upon the toilet seldom produces adequate results, so only take one while on the toilet when it is the only alternative.
  2. Wrong temperature.- An enema solution too cool can cause excessive cramping. If it is too hot it can damage the delicate mucosa lining the bowel. Body temperature or slightly above (98-105F) is just right.
  3. Too much pressure.- If the bag or can is suspended too high, excessive pressure can cause severe discomfort. The bag should be just high enough to allow the solution to barely flow. Don’t worry how long the enema takes. The slower you go the more solution you will be able to take without discomfort.


  1. Use a sufficient volume of solution.- The major factor in an enema’s effectiveness is an adequate amount of solution. Many medical books suggest that a pint or so is sufficient, but any experienced nurse will tell you that good results are rarely obtained with such a small amount. What usually happens in the case where an insufficient amount is used is that the entire procedure must be repeated. It is a lot easier and more comfortable to do it right the first time.
  2. Retain the solution for 5 to 15 minutes.- Retaining the enema for a while before expelling it can significantly contribute to good results. Many people find it surprising that this can have such a major impact on an enema’s effectiveness, but experience has shown that it really works. Try and retain the enema for 15 minutes if possible, (it is often very uncomfortable, and one minute seems like 10). At least five minutes should be the absolute minimum. During this time the enema has time to work it’s way up into the upper recesses of the bowel, soften the movement in general, and dissolve the hard caked fecal coating on the interior wall of the bowel.

Escala de heces (Bristol stool chart)

31 julio 2009

Bristol Stool Chart

La Escala de heces de Bristol o Gráfico de heces de Bristol es una tabla visual de uso en medicina destinada a clasificar la forma de las heces humanas en siete grupos. Fue desarrollada por K. W. Heaton y S. J. Lewis en la Universidad de Bristol y se publicó por primera vez en el Diario escandinavo de gastroenterología en 1997. La forma de las heces depende del tiempo que pasan en el colon.

Los siete tipos de materia fecal son los siguientes:

  • Tipo 1: trozos duros separados, como avellanas, que pasan con dificultad.
  • Tipo 2: como una salchicha compuesta de fragmentos.
  • Tipo 3: con forma de salchicha con grietas en la superficie.
  • Tipo 4: como una salchicha o serpiente, lisa y suave.
  • Tipo 5: bultos blandos con bordes definidos, que pasan con facilidad.
  • Tipo 6: fragmentos blandos con bordes irregulares y consistencia pastosa.
  • Tipo 7: acuosa, sin pedazos sólidos, totalmente líquida.

Los tipos 1 y 2 indican estreñimiento; los 3 y 4 son heces ideales, especialmente el 4, ya que son los más fáciles de defecar; los tipos 5, 6 y 7 tienden a la diarrea o el cólera.

Anatomía anorectal

3 julio 2009

El recto y el canal anal forman la zona terminal del tubo digestivo. El recto es la continuación del colon, con el que forma un ángulo agudo que dista unos 12-15 cm del margen anal externo. Tiene una morfología fusiforme y su mucosa muestra tres pliegues que contienen músculo liso circular.


El límite inferior, la línea pectinea, es la unión embriológica y macroscópica entre el ano y el recto, se llama así porque asemeja a un peine. Intervienen en su constitución: Valvas, pilares y papilas de Morgagni, que constituyen las criptas de Morgagni.

En las criptas de Morgagni desembocan las glándulas de Chiari, glándulas sudoríparas atróficas en nuestra especie, cuya inflamación produce trayectos fistulosos y abscesos perianales.

Las válvulas de Houston, normalmente son tres: La 1ª y la 3ª están a la izquierda , la 2ª ocupa el lado derecho. Cada una ocupa un tercio de la circunferencia y adopta la forma semilunar con la concavidad hacia arriba; describen un plano inclinado en espiral que aparentemente favorece la progresión del cilindro fecal.

La unión rectosigmoidea representa un estrechamiento a la luz rectal.

La porción distal del recto, al penetrar en el diafragma pélvico, se transforma en el canal anal, tras ser rodeada fuertemente por su musculatura.

El canal anal mide 3-4 cm y está rodeado por un doble anillo muscular constituido por el esfínter anal interno, engrosamiento final del músculo circular del recto, y el esfínter anal externo, músculo estriado compuesto por tres fascículos. La porción media del canal anal es rica en glándulas anales. Además, en esta zona encontramos el plexo hemorroidal interno y externo, asiento de las hemorroides.

La vascularización arterial del recto depende de la arteria hemorroidal superior y de la hemorroidal media, y la vascularización del canal anal obedece a las arterias hemorroidales inferiores.

El recto y el esfínter anal interno son inervados por los sistemas nerviosos simpático y parasimpático, y el esfínter anal externo por nervios somáticos. La sensibilidad perianal y del canal anal depende de los nervios rectales inferiores.