Causes. The causes of bowel obstruction are varied. Mechanical causes include adhesions. These are bands of tissue that can block the intestines. They are often a complication of surgery. Other causes are intestinal hernias, benign or malignant tumors or inflammation. The person with a blockage can suffer from an inflammatory bowel disease such as Crohn’s disease. Sometimes, foreign bodies cause the blockage. These can range from swallowed objects, gallstones or even parasites. Another cause is the bowel telescoping into itself and becoming a tube inside of another tube. This is called intussusception and happens mostly to babies and very young children. The bowel can twist and cause a blockage, or the person can suffer from a fecal impaction. This is a large, hard stool that they can’t pass. It’s most often found in the rectum, or the lowest part of the large intestine.
Non-mechanical reasons for a bowel obstruction include certain drugs. Opioids are notorious for causing bowel contractions to shut down. Another cause is something that interferes with the blood supply to the intestines. This can be the result of an injury. A blockage can be caused by an infection, kidney disease, a disease in the chest cavity or problems with the person’s metabolism. People who are deficient in potassium sometimes have bowel obstructions.
