Bowel obstruction occurs in about 3% of patients with advanced cancer, most commonly with cancers of the ovary (25%) and colo-rectal cancer (10%), but occasionally with endometrial, prostate, bladder and stomach cancers, and lymphomas.

In cancer patients who develop intestinal obstruction it is often assumed that recurrent tumor is responsible. However, severe constipation can mimic obstruction.

Assessment – Symptoms can include:

  • Continuous pain

  • Colicky pain

  • Nausea

  • Vomiting

  • Constipation

  • Diarrhea

  • Abdominal distention

Colic causes episodic severe pain (i.e., the severity of the pain fluctuates) and it can be associated with bubbling bowel noises (borborygmi) and also nausea. It does not respond to opioids, but responds to an anti-spasmodic such as scopolamine.

Diarrhea can occur as well as constipation – intestinal dysfunction is often a more correct term than “obstruction”, because the obstruction can be intermittent and bowel function can return spontaneously after a few days.

Make the distinction between nausea (a very unpleasant symptom, albeit invisible) and vomiting (which the patient may not find too distressing if it is intermittent).

Assess distention. Is it gaseous, or is it in fact ascites which could be relieved by paracentesis? Large tumor masses preclude surgery. Lack of distention suggests extensive fixation of bowel by tumor deposits and means surgery is unlikely to help. Perform a rectal examination to exclude constipation.

Plain abdominal x-rays may show fluid levels. Barium studies are useful and can usually delineate a large bowel obstruction.

Management options:

  1. Surgery

  2. Suction and rehydration (“conservative management”)

  3. Continuous subcutaneous infusion of drugs (“symptomatic management”)

1. It is important to consider surgery in a cancer patient who develops obstruction for the first time, because:

  • 10% have a benign cause

  • 10% have a new primary cancer

  • A majority will not re-obstruct

Carefully selected patients can get useful palliation for several months. On the other hand, operative morality is high (14% to 32%).

If obstruction recurs, medical management focusing on symptom control is usually a better option for the patient than further surgery.

2. In conservative management, naso-gastric suction and IV rehydration are important if surgery is planned, but they should not be used to control symptoms, since they are rarely effective and only add to the discomfort of terminally ill patients. They usually involve hospitalization, immobility and discomfort and should be avoided. In terms of symptom control, most studies show a poor response rate (1 % to 14%) for conservative management.

3. Symptomatic management with drugs (usually via continuous subcutaneous infusion using a small, portable battery-operated pump) can effectively control symptoms and has several advantages:

  • Patient can eat and drink

  • Patient can be mobile

  • Home care is possible

In a study of 40 hospice patients with intestinal obstruction treated medically it was possible to abolish symptoms in the majority of cases. (Only 30% of patients continued to have mild symptoms of visceral pain, colic or nausea. 76% of patients continued to have mild vomiting - not more than one episode per day with little or no nausea.)

Controlling symptoms – A continuous subcutaneous infusion using a small, portable battery-operated pump is usually the best route for drug administration, although mild or intermittent pain can be controlled using other routes (sublingual, rectal, IM injection).

The drugs commonly used (mixed together) in a continuous subcutaneous infusion are:

  • Morphine or hydromorphone – for visceral pain

  • Scopolamine – for colicky pain (0.8mg to 2.4mg per 24 hours)

  • Haloperidol – for nausea (5mg to 10mg per 24 hours)

The dose of opioid analgesic needs to be carefully titrated to the pain, and will depend on the dose of opioid analgesic that previously controlled the pain.

If nausea persists then stronger anti-emetics are required instead of haloperidol. Use cyclizine 100mg to 150mg per 24 hours, or methotrimeprazine 50mg to 100mg per 24 hours. (see Subcutaneous Infusions)

The aim of symptomatic management is to control pain and nausea, and to allow fluids and a soft diet. Some food is absorbed in the upper small bowel above the obstruction. Occasional short episodes of vomiting once or twice a day may have to be accepted. Patients usually tolerate vomiting well, provided they are free of nausea and receive appropriate explanation.

A fecal softener (docusate sodium syrup 100mg to 200mg every 8 hours) is given so that if bowel function is restored (which it can be) constipation is not an additional problem. Stimulant laxatives should be avoided as they worsen the colic.

«  This regime can keep patients well hydrated and virtually free of symptoms for many weeks.

The author and publisher have taken precautions to ensure that the information in this book is error-free. However, readers must be guided by their own personal and professional standards of good practice in evaluating and applying recommendations made herein. The contents of this book represent the views and experience of the author, and not necessarily those of the publisher.

3 Unity Square • P.O. Box 98 • Machiasport, Maine 04655-0098 • U.S.A.
Hospicelink 800.331.1620 • Telephone 207.255.8800
Telefax 207.255.8008 • hospiceall@aol.com.