A fecal impaction is a hard mass of stool in the rectum, too large to pass through the anus without causing severe pain or tearing. Fecal impactions are usually caused by chronic constipation, which may be related to diet, lack of exercise, overuse of laxatives, or neuromuscular disease (such as multiple sclerosis). You may have bloody discharge or watery stool leaking around the impaction and will usually feel crampy and bloated with pain and pressure in the rectal area.
Oil Retention Enema
Doctors Schueler, Becket, and Gettings at FreeMD outline options for treatment. Laxatives are rarely effective for an impaction. An impaction may be one large mass of hard stool or many small and large balls of hard stool clumped together. You need to do a rectal exam (gloved finger) to determine the size and consistency of the impaction and then instill an oil retention enema along the side of the impaction. You should try to retain the oil for 30 minutes. The oil provides lubrication and softens the stool, and this may be enough to let you pass all or part of the stool in the rectum.
Breaking Up Impaction
If the oil retention enema is not successful, you must remove the impaction manually to prevent injury to the anus, rectum and large intestine, which can stretch or tear. You insert a gloved finger into the rectum and gently break up the stool. (Ideally someone will do this for you.) You may be able to remove small balls of stool, but you shouldn't attempt to remove the entire impaction at one time as it's very uncomfortable. You may use glycerine or bisacodyl suppositories between manual removal to stimulate the bowel, continuing to break up the stool until the rectum is empty. Because you may have impacted stool higher in the colon, you should follow this with a tap water enema (about a pint of water at one time) or Fleet sodium phosphate enema as this stimulates contractions and helps to move stool further down the colon to the rectum.
Preventing fecal impaction requires that you increase fiber in your diet (bran, fruits, vegetables), increase fluids to 2 quarts daily and increase your exercise. Walking is ideal exercise because the movement stimulates bowel contractions. According to the University of Maryland Medical Center, you should avoid the use of laxatives as they worsen constipation and interfere with normal bowel activity; however, you should take daily stool softeners and may need a bulk former (such as Metamucil®) as well. It's important not to delay toileting when you feel the urge to defecate. You may need to reestablish a regular bowel routine by using glycerine suppositories at the same time each day to stimulate the bowel until your bowels move on a routine schedule.