Bowel obstruction refers to blockage of the intestinal tract. This most commonly affects the colon or small bowel, but can occur in the stomach or esophagus as well. Small bowel obstruction is much more common than colonic obstruction, with colon cancer being the most common cause of colon obstruction. That said, colon cancer presents with obstruction in only 2-3% of cases.
Small bowel obstruction results from either partial or complete blockage of the intestinal lumen. This can be the result of a variety of causes.
Adhesions in 60%
Inflammation from diseases such as Crohn’s, ulcerative colitis, and diverticulitis in 5%
As can be seen, adhesions are the most common cause of obstruction. An adhesion represents scar tissue which forms after surgery. They are the most common cause of small bowel obstruction as noted. Adhesions can occur after any abdominal surgery. They are more common after extensive surgeries such as pelvic or colon surgeries. Adhesions can result in torsion/twisting of the bowel…much like we see with a garden hose. This results in kinking of the bowel and possible compromise of the blood supply
Tumors/cancers can also cause obstruction. This is most commonly seen with metastatic cancers from the outside of the bowel. Small bowel cancers are rare, and colon cancer presents with obstruction in only a small percentage of cases (2-3%). The most common types of cancer causing obstruction include ovarian, pancreatic, stomach, colon, lung, and breast. The obstruction is caused by direct invasion and compression of the bowel.
Hernias can also cause obstruction and are a result of a loop of small bowel or colon becoming trapped within the hernia. Inflammation of various cause can also result in scarring and blockage of the bowel…Crohn’s, ulcerative colitis, diverticulitis.
Patients with obstruction present with crampy abdominal pain, abdominal distension, and eventually nausea and vomitting. They will stop passing stool or gas after the intestinal tract below the obstruction has emptied. The continued passage of small amounts of gas and stool while still having symptoms is indicative of a partial obstruction.
Our evaluation consists of a good history and physical exam followed by basic laboratory studies and Xray/CT scan to make the diagnosis.
Treatment consists of IV fluid support, use of a nasogastric tube to decompress the bowel, and repeat examination of the patient. Approximately 50% of patients will have spontaneous resolution of the obstruction…as the same spontaneous process of rotation which caused the problem may reverse itself. If the patient shows no improvement in 24-48 hrs, or deterioration in condition, surgery is warranted. Simple lysis (division) of adhesions is all that is required in most cases. This can sometimes be done by minimally invasive surgery. Reduction and repair of hernia is done when an incarcerated hernia is the cause of obstruction. More extensive surgery may be required for more serious causes.
Patients often ask…”how can I prevent this from happening”? The honest answer is that there is no proven method of prevention. Surgeons attempt to minimize the ‘injury’ caused by surgery, hoping to minimize risk. Even with this, an obstruction can occur at any time in a patient who has had abdominal surgery. They are not caused by diet or activity. It is important for patients to recognize the symptoms and seek medical care if they develop any of the symptoms described above.