Intestinal Obstruction

The digestive tract or GI tract is made up of the oesophagus, stomach, small intestine, and large intestine. It is part of the digestive system.

The small intestine digests nutritions from food and liquids, and absorbs them into the blood vessels. These nutritions include proteins, fats, and carbohydrates. Remaining food that cannot be digested moves from the small intestine to the large intestine. The colon absorbs water from the waste and stores waste until the next bowel movement, which discharges the waste as stool from the body.

An intestinal obstruction is when a blockage stops food and liquids from moving through the digestive tract. It is also called a bowel obstruction, blocked intestine, or a gastrointestinal (GI) obstruction.

A complete obstruction is a medical emergency and may require surgery, while a partial obstruction should also be taken seriously and needs to be treated right away. It is important to seek medical advice as soon as possible if any of the symptoms of bowel obstruction appear.

The common causes of bowel obstruction in patients with cancer include:

• A tumour or tumours inside the GI tract
• A tumour or tumours against the exterior of the GI tract
• Twisting of the intestines
• Scar tissues or adhesions that form on the small or large intestines after surgery
• Inflammation of the intestines after radiation therapy
• Fecal impaction, which is when dry and hard stools build up in the rectum due to chronic constipation

Bowel obstructions can happen in many types of cancer. They are more common in people with:

• Colorectal cancer 
• Stomach cancer
• Pancreatic cancer
• Ovarian cancer
• Uterine cancer

Symptoms of a bowel obstruction include:

• Nausea and vomiting
• Abdominal pain
• Abdominal cramps
• Abdominal distension
• Visible waves of movement across the belly from peristalsis contractions
• Bad breath
• Feeling food get stuck as it moves through the GI tract
• Not being able to pass stool or gas

To diagnose bowel obstruction, doctors will perform a physical exam; in which they feel and listen to the abdomen with help of a stethoscope.

Bowel obstruction can often be confirmed with an abdominal X-ray. However, not all bowel obstructions will be displayed on an X-ray.

Figure: A 67-year-old gentleman was diagnosed with colon cancer, which was complicated with small bowel obstruction.

Abdominal X-ray showed dilated bowels and air-fluid levels.

Case courtesy of Dr Henry Knipe, <a href="https://radiopaedia.org/?lang=us">Radiopaedia.org</a>.

From the case <a href="https://radiopaedia.org/cases/27836?lang=us">rID: 27836</a>

Possible alternatives include:

• CT scan, or 
• barium enema

Most patients with bowel obstruction require hospitalisation. The best treatment for a bowel obstruction depends on its cause. Some ways to treat or manage a bowel obstruction are:

• Resting the bowel: Fasting for a few days can help reset and reverse twisted bowels. Patients will be given an intravenous fluid to keep them hydrated and their electrolyte balanced. If the blockage does not improve after a few days, IV nutrition may also be needed.
• Relieving pressure in the abdomen: A nasogastric tube, which goes down into the stomach through the nose, may be inserted to relieve pressure in the abdomen while preventing the patient from vomiting.
  
• Medicine: Doctors may prescribe medications to relieve nausea and vomiting, constipation, swelling, or pain.
• Surgery: Surgery may be applicable to some of the patients. Surgical options include:
  • Resection of the obstructing mass/ by-pass surgery: Surgery to open the blockage and clear a path for food to go through the GI tract.
  • Stenting: A stent which is an expendable tube, that can be placed in the bowel to temporarily open the blocked area of the GI tract.
  • An ileostomy/ colostomy: This surgery helps the large intestine and rectum heal after a blockage. During an ileostomy, a temporary or permanent opening (stoma) is made from the lowest part of the small intestine to the outside of the abdomen. Waste is collected in a pouch worn on the outside of the body, and does not need to pass through the large intestine or the colon.

Relieving discomfort

Some patients may have refractory bowel obstruction, which means the obstruction cannot be relieved by medications or surgical interventions. Below are suggestions on reliefing discomfort:

• Smelling an open lemon
• Drinking honey water to moisturise the mouth
• Massaging the abdomen or placing a warm pad over the abdomen
• Having more meals a day but less food at each. It is also better to consume fluids.
• Taking sweet ginger soup, which may relieve some gastric discomfort
• Taking a few mouthfuls of Coke to relieve gas pain
• Going for a short walk

American Society of Clinical Oncology: Bowel obstruction

Canadian Cancer Society: Bowel obstruction

Special thanks to Mr. Joshua Tang and Dr. Wendy Wing-Lok Chan, Department of Clinical Oncology, the University of Hong Kong for authoring and editing this article.

Last updated on 1 Nov 2021.