Severe constipation can lead to bowel or fecal impaction, a condition where solid stool accumulates in the rectum and large intestine, hardening and making a normal bowel movement impossible. Bowel impaction occurs most frequently in the elderly, the infirm and mentally challenged, people who take large amounts of narcotic medications, which can slow intestinal movement, and in people with spinal cord injuries. Small amounts of liquid stool may pass by the impaction, the Merck Manual explains. Abdominal distention, pain, nausea, vomiting and appetite loss often occur. Serious complications can result from fecal impaction.
Digital removal of the impacted stool can damage the delicate mucosa, the tissue that lines the bowel, causing rectal bleeding. Fecal impaction is removed in small steps to minimize tissue damage, MedlinePlus states. Enemas used before manual removal attempts may soften and lubricate the stool, making manual removal easier. Ulceration or necrosis, or death of the bowel, can occur from pressure on the bowel walls, the Encyclopedia of Nursing and Allied Health warns. Necrotic tissues may need surgical removal.
Untreated fecal impaction can cause the bowel to become massively swollen and dilated, a condition called megacolon, according to the Encyclopedia of Nursing and Allied Health. Megacolon makes it hard for the bowel to contract and move stool through the colon and often requires surgical repair.
Digital removal of impacted stool can cause vagal nerve stimulation, the Encyclopedia of Nursing and Allied Health states. Vagal nerve stimulation can lead to irregular heart rhythms, weakness and fainting. In rare cases, cardiac tamponade, compression of the heart that prevents the ventricles from expanding completely and pumping out normal amounts of blood, develops, Mark Truty, M.D. of the Mayo Clinic reported in the 2010 "Journal of Family Practice Medicine".
Complete bowel obstruction can require surgical removal of the impacted stool if efforts to dislodge the stool with laxatives or digital removal fail. Bowel obstruction can lead to perforation and death.
Perforation of the bowel with spillage of stool into the abdominal cavity and peritonitis, infection of the cavity, can cause death if not promptly treated. People who use steroid medications long-term and develop bowel impaction are especially prone to perforation. Steroids thin the bowel wall and increase the chance of perforation in people with fecal impaction, and also suppress the immune system, decreasing the body's ability to fight infection. In addition, steroids mask the presence of infection, delaying diagnosis, Truty states.