Common causes for a blocked bowel include adhesion, diverticular disease, hernia, colorectal cancer and paralytic ileus. These causes affect the small intestine and colon, and their effects can occur from inside or outside the intestine. A blockage can result from a swelling in the inside of the intestine or when an external organ compresses a segment of bowel, according to Drugs.com.
Adhesions are scar tissues that develop after an abdominal surgery or infection. These tissues bind on the neighboring loops of intestine, causing mechanical bowel obstruction. Paralytic ileus can also cause this condition, interfering with the wavelike muscle contractions of the digestive tract and preventing the movement of contents along the alimentary canal. Some of the risk factors for paralytic ileus include kidney failure, heart attack, diabetes and an insufficient production of thyroid hormones, notes WebMD.
Sometimes, a portion of the intestine may push through a weak area in the wall of the abdomen, blocking the bowel, a condition called hernia. Diverticular disease may also affect the digestive tract, making small bulges to develop in the walls of the intestine. During the healing process, scars may form, narrowing the large intestine with time and causing a blocked bowel. Moreover, rectal or colon cancer may cause a gradual narrowing of the colon, interfering with smooth passage of contents through it, explains Drugs.com