​Digital Stimulation Review

Occasionally, I hear a topic come up that is questionable. It is usually an isolated case, so that can be discussed and education provided. Coincidentally, it may pop up in another setting and then another. Red Alert. Time to set the record straight. The issue currently being misinterpreted is the digital stimulation of the rectum.

More than likely, digital stimulation is misconstrued because people just do not want to talk about bowel programs and are uncomfortable with the discussion. This is not only in the community but in healthcare as well. Faster rehabilitation stays are making education about bowel care shorter, which does not allow for time for questions that pop up as an individual learns the process. Education of healthcare providers does not linger over the finer points of bowel care as well.

Digital stimulation is a process used in bowel evacuation for individuals with upper motor neuron neurogenic bowel or those with a reflexive bowel that has tone. This type of bowel occurs in some brain injuries and in those with spinal cord injury in the cervical (neck) or thoracic (chest) areas. These are individuals who have difficulty expelling stool from the bowel. Individuals with a lower motor neuron neurogenic bowel, or those with an areflexive or flaccid bowel in some brain injury or in the lumbar (curve of the back) or sacral (shield or tail of the backbones), utilize manual removal of stool from the rectum.

The bowel has two sphincters. You can see the external sphincter as it opens the rectum to the outside of the body. This sphincter is the opening from the body to the outside world. It is under the control of the somatic nervous system, which means you have voluntary control over this opening. Without neurological issues in bowel function, the external sphincter is under the control of your mind. If you have the urge to pass stool, you can mentally tighten the external sphincter to hold the stool until you are in a location where you can relax the external sphincter to eliminate the stool from your body. The same action can be used to stifle passing gas. If you have a neurogenic bowel due to neurological injury or disease, the mental control function of this sphincter is affected.

The other sphincter in the rectum is the internal sphincter which is about 3-4 inches inside the rectum from the location of the external sphincter. You cannot visually see the internal sphincter, but it is there. This sphincter is controlled by the autonomic nervous system (ANS), the part of the nervous system that is not under your mental control but under the automatic control of the ANS. After nervous system disease or injury to the upper spinal cord or part of the brain that controls the ANS, this sphincter becomes reflexive or maintains a tone of continuous spasticity. In other words, it is maintained in a closed state. Stool will not pass through the affected internal sphincter. There can be some occasions when the pressure in the bowel becomes so strong that it overwhelms the internal sphincter leading to incontinence but not fully emptying. Mostly, the internal sphincter remains tightly closed in upper motor injuries.

This is when digital stimulation becomes a necessity. The purpose of digital stimulation is to relax the internal sphincter of the bowel to allow stool to pass. Digital stimulation is performed by using a gloved, well-lubricated index finger to relax the internal sphincter. The external sphincter is already relaxed in neurological conditions as the mental control over this sphincter is reduced. Due to the neurological issue, constriction of your external sphincter is not an issue, so that is not the area of concern. The automatically ANS-controlled internal sphincter remains tight unless it is manually relaxed.

This seems to be a point of confusion. People are taught to relax the sphincter. Not realizing there is an external sphincter and an internal sphincter, they see the external sphincter and just insert the finger less than half of an inch to relax it. But that is not the sphincter that needs relaxing!

The target is the contracted internal sphincter. You need to insert a well-lubricated finger fully into the rectum to reach the internal sphincter. Interestingly, your own index finger will be just the right length. If you have a caregiver providing digital stimulation who is a much smaller individual, they may need to use their middle finger. Some will be able to feel the internal sphincter and will feel it relax as digital stimulation takes place. Most will not feel the internal sphincter with their finger but coming close to it will still relax it as the stimulation travels through that section of the bowel.

Since the upper motor neuron, neurogenic bowel is reflexive; it has tone. This is why the internal sphincter stays closed, it has tone as well. Rough stimulation or aggressive stimulation increases tone (spasticity). Therefore, digital stimulation should be performed gently to calm the spasticity, not increase it. Most individuals want to get this job over quickly so they move as fast as they can, but this only serves to prolong the bowel program process as quick, fast, aggressive digital stimulation to the internal sphincter closes it even tighter. This can greatly delay the bowel program time. It is one of the most often issues causing bowel program times to be extended or even nonproductive.

Only one well-lubricated finger should be used. Additional fingers do not help. The bowel is an elastic organ made of stretchy muscle. Inserting things larger than one finger width can stretch out the neurogenic bowel making it less able to snap back into its normal position. Passing stool through an overstretched bowel is difficult in the already challenged neurogenic bowel. This includes letting stool collect in the bowel which overstretches the bowel muscle. Impactions or build-up of stool from not performing a bowel program create overstretching and impaction issues.

The tissue inside the body is not as hearty as the skin on the outside of the body. Skin is very sturdy as it protects the inner body from the environment. The tissue inside the body is far more delicate as it has great protection from the skin. Using a dry finger or one wet with water is too damaging for the delicate bowel tissue when doing the bowel program. Generous lubrication applied to the finger will free the bowel's tissue from complications such as tears, hemorrhoids, ruptures, or other issues. Maintaining the interior lining of the bowel can help avoid infections from entering. A gloved finger keeps infection from entering around your nails or open areas on the finger.

If you have limited hand/finger function, you may choose to use a suppository inserter and/or digital stimulation device. The suppository inserter has a tip that the suppository can be attached with easy removal in the rectum. The digital stimulator has a different tip that has a bit of ‘give’ to gently stimulate and relax the internal sphincter. Both should be lubricated before insertion for tissue protection. Digital stimulation devices should be used as gently as possible to avoid tissue damage as well as for their main purpose, to relax the internal sphincter.

Manual removal of stool is different from digital stimulation. Individuals do this procedure with lower motor neuron neurogenic bowel, which is areflexic or without tone (spasticity). However, individuals with reflexive bowel also need to do it at times. In this process, the gloved, well-lubricated finger is inserted into the rectum and used as a ‘hook’ to bring stool out of the body. Those with areflexic bowels do this for their bowel program. Those with reflexic bowel may need to remove stool so a suppository can be inserted next to the bowel wall to work by stimulation. Suppositories only melt when against the bowel wall using body heat. Mini-enemas work with contact to the bowel wall to trigger nerve stimulation. Neither works when placed in the middle of stool.

As with any procedure or activity, the subtle nuances make a huge difference. Sitting for the evacuation period of the bowel program provides an assist from gravity for the stool to be expelled. Performing the bowel program, including careful consideration of digital stimulation, can make big improvements in bowel program completion, timing, and safety. Nurse Linda

Pediatric Consideration:

Children’s bodies are much smaller, so an adult finger may be too large for digital stimulation. The little finger of an adult hand is adequate for infants and small children, both for suppository insertion and digital stimulation. As the child grows, you will eventually move to a longer finger. One way to check is to look at the size of the child’s finger compared to yours, as the child’s finger size is just right for them. Also, your healthcare provider can assist with deciding when to move to a longer finger.

Teaching your child to do their own bowel program will be normal for them. Performing the bowel program is much easier than the bladder program as there is less risk of infection. Teaching your child to be gentile will be very important as children and teens have many other things that interest them, so they may rush ahead.

Keep in mind that parents do not take older children to the restroom, so you will want to transfer this activity to the child to increase their independence. About the time of potty training is a good age to begin the process. Always, even as an infant, tell the child what you are doing so the steps to the bowel program are known. Then transition, the process to the child over time, making the complete transition well before going to school.

Teens can have their own set of challenges. Waiting for a bowel program to work can be time-consuming but teaching them the proper techniques, including gentle digital stimulation, will speed up their time doing a bowel program, not slow it down when done incorrectly or too quickly.