How Does a Bowel Obstruction Occur?

Symptoms

Bowel obstruction occurs when the bowel is blocked, either mechanically (literally blocked off) or functionally, which does not allow food to pass along the normal process for digestion. Obstructions can occur as a result of problems with the bowel lumen (the lumen is the inside wall of the bowel), within the bowel wall, or outside of the bowel. Common symptoms of a bowel obstruction include pain and swelling of the abdomen, vomiting (which can include vomiting of feces) and constipation.

Causes of Small Bowel Obstruction

Small bowel obstruction, also known as obstruction of the small intestine can happen due to a number of causes. In some cases, abdominal surgery can cause the walls of the small intestine to stick together. Hernias that include portions of the small intestine can also cause it to become blocked. Tumors can also cause small bowel obstruction. Another type of blockage, called strictures, occurs when the walls of the small intestine swell and block off the area. This can be due to Crohn's disease or from a lack of blood. Finally, foreign bodies, such as gallstones and swallowed items can block the large intestine.

Causes of Large Bowel Obstruction

Because the large intestine comes after the small intestine and is bigger in diameter, it can be harder to obstruct. Nevertheless, some types of tumors are able to block off the comparatively large space. Again, hernias that wrap around the bowel can also block it off. Inflammatory bowel disease as well as "benign strictures" (which are essentially swellings of the intestinal wall that have no known cause) can also block off the bowel. Finally, fecal matter can also become stuck, obstructing the end of the large intestine.