What is bowel obstruction? The bowel, or intestine, is the part of the digestive tract that absorbs nutrients and fluid from foods we eat. The residue of digested food passes through the bowel and is excreted during elimination, the final stage of digestion. This process can be interrupted or halted by the presence of a bowel obstruction, which is a blockage that prevents the passage of intestinal contents. The cause of the blockage can be mechanical, meaning that there is a physical obstruction. Mechanical blockage may be caused by scar tissue, adhesions, entrapment through a hernia, foreign bodies, gallstones, tumors, impacted feces, and volvulus (twisting of the intestines). Treatment for mechanical obstruction generally involves removing the source of the blockage, if possible. Ileus, a malfunctioning of the synchronized contractions of the bowel, is another type of obstruction. Causes of ileus include electrolyte imbalances, gastroenteritis (inflammation or infection of the stomach and intestines), appendicitis, surgical complications, and obstruction of the mesenteric artery, which supplies blood to the abdomen. Certain drugs and medications can cause ileus, such as opioids and sedatives, which slow down peristalsis, the contractions that propel food through the digestive tract. Bowel obstruction can produce symptoms, such as a distended abdomen, fullness, gas, painful spasms, constipation, diarrhea, nausea with or without vomiting, and foul-smelling breath. Treatment options include surgical placement of a tube through the stomach or nose to alleviate the distension and remove the obstruction. Some forms of bowel obstruction, such as those caused by paralytic ileus, may go away on their own. Bowel obstruction is a serious medical condition that should be evaluated immediately by a health care provider. Seek immediate medical care (call 911) if you develop symptoms of bowel obstruction, such as abdominal pain, distension, or bloating, and are unable to eliminate feces or pass gas.