An impacted bowel, sometimes called a fecal impaction, happens when a large ball of dry, hard stool gets stuck in the rectum, according to MedlinePlus. The blockage of stool can become so hard that it can't be eliminated and blocks the intestine. The stool backed up behind the blockage sometimes seeps out around it, causing soiling or diarrhea. Though the condition is treatable, it can cause tearing in the rectum or even tissue death.
Chronic Constipation
Chronic, severe constipation is the chief cause of impaction, according to MedlinePlus. This is particularly a problem for bedridden patients who have limited ability to move, which can lead to difficulties with bowel movements.
Drugs
Certain drugs can cause the kind of chronic constipation that leads to impaction, according to MedlinePlus. These include anticholinergics, which affect the interaction between nerves and muscles; diarrhea medications; methadone treatment for drug addiction; and narcotic painkillers.
Other Factors
Sometimes there are mechanical issues with the bowel that can lead to obstruction or impaction, often because the colon has been narrowed, according to Mayo Clinic. These include cancer; swelling or inflammation from an intestinal disease, such as Crohn's disease or diverticulitis; twisting or narrowing of the colon; and sometimes swallowing objects that block the colon. Sometimes scarring from abdominal surgery, hernias, tumors or other conditions make it difficult for food to move smoothly through your digestive tract and that can lead to a blockage, explains The Merck Manual of Medical Information.
