Malignant Bowel Obstruction

NCI's instruction is short and firm. If you think you have a bowel obstruction, contact your doctor right away. Bowel obstructions can be life-threatening and require immediate medical attention.

MedlinePlus sets the same level. Contact your provider if you cannot pass stool or gas, have a swollen abdomen that does not go away, keep vomiting, or have unexplained abdominal pain that does not go away.

So ring your cancer team or palliative care team straight away. Not a portal message, not tomorrow. If you cannot reach them, or you cannot get assessed in person quickly, or the pain and vomiting are severe or getting worse, go to an emergency department. Call 911 for collapse, confusion, severe breathing difficulty, or any other sign that someone is becoming unstable.

These are the signs NCI lists:

• Abdominal pain or cramps.
• Swelling in the abdomen.
• Constipation.
• Diarrhea.
• Nausea or vomiting.
• Problems passing gas.
• Loss of appetite.

No clinician has reviewed this page yet. Your palliative care or oncology team's instructions come first.

It looks like a mistake. It is not.

NCI's health professional page describes overflow diarrhea as a rare feature of malignant bowel obstruction: liquid stool works its way past the blockage while everything solid stays put. So loose stool does not rule an obstruction out, and neither does passing a small amount of anything.

This is the difference between this page and the other emergency pages on this site. A blockage often builds over days.

NCI describes it as a progression. When an obstruction starts, the intestines may be only partly blocked, causing a few mild symptoms. As it worsens, the symptoms come more often and get more severe.

Then it names the picture of a complete blockage: frequent vomiting, extreme bloating, and intense abdominal pain. At that point stool and gas are mostly or totally blocked from leaving the body.

That slow build is a chance and a trap. A chance, because reporting the mild version early gives more options. A trap, because mild symptoms are easy to explain away as constipation, or as the chemotherapy, or as a bad week.

Worth writing down before you ring: when you last passed stool, when you last passed gas, how many times you have vomited and what it looked like, whether the belly is bigger, and what the pain does.

Constipation and an obstruction feel similar from the inside, and the home remedies for one are not right for the other.

NCI's guidance for constipation in cancer is to use only medicines and treatments for constipation that your doctor recommends. That is the whole of it: this is a decision the team makes, not one to make at home with what is in the cupboard.

NCI is more specific still about the two things people reach for last: do not use suppositories or enemas unless your doctor recommends them, because in some people with cancer they may lead to bleeding, infection or other harmful side effects.

There is also a cause worth knowing. MedlinePlus lists certain medicines, especially narcotics, among the causes of paralytic ileus, where the bowel stops working properly without anything physically blocking it. Opioid pain medicines are common in advanced cancer. So the pain relief and the bowel problem can be connected, and that is a specific thing to raise.

NCI splits the causes.

Cancer treatment can do it. Surgery on the abdomen or pelvis leaves adhesions, scar tissue that can bind the intestines together. Radiation to the abdomen can damage the intestines and cause scarring, inflammation and radiation enteritis.

Cancer itself can do it. A tumor can form in the bowel, press on it from outside, or grow where it affects the nerves that move food along. NCI says cancers that form in the abdomen, such as colon, ovarian, pancreatic or stomach cancer, are more likely than other types to cause a blockage, and that advanced cancer is the most common cause of a malignant bowel obstruction.

Which of these it is changes what can be offered, which is why the team will ask about old operations and old radiation fields.

NCI says a bowel obstruction is treated in hospital, and that a complete blockage will probably need surgery while a partial one may clear with other treatments.

• Bowel rest. Avoiding food and drink so the obstruction does not get worse, usually with fluids given into a vein.
• Nasogastric tube. Passed through the nose into the stomach to remove fluid and gas, which relieves pressure and helps control nausea, vomiting and pain.
• Stent. A tube placed in the intestine to open the blocked area. NCI's health professional page notes that stents used to decompress a complete, acute malignant obstruction have been found to reduce the number of unnecessary operations.
• Surgery. One option among several, and not right for everyone. Depending on where the blockage sits and how well someone is, an operation might remove the tumour, bypass the blocked segment, or bring the bowel out to the skin as a stoma. The goal can be to clear the obstruction or simply to relieve symptoms. Surgeons weigh this against how much it would take out of the person.
• Venting gastrostomy tube. A tube through the abdominal wall into the stomach, attached to a drainage bag with a valve, to let fluid and air out.
• Antibiotics. If the obstruction tears the intestine, fluid leaks into the abdomen and can cause sepsis. Antibiotics are used to prevent tissue damage, organ failure or death from it.
• Antinausea and pain medicines. NCI's health professional page names octreotide among the drugs used, and says it may reduce the nausea, vomiting and abdominal pain of malignant bowel obstruction.

Diagnosis is usually a CT scan, which NCI says finds both the cause and the exact location. An abdominal x-ray can show where the blockage is but is less sensitive. Blood tests and urinalysis check for dehydration, electrolyte problems and infection.

This is the part that makes malignant bowel obstruction different from every other emergency here.

NCI puts it in plain words. For a malignant bowel obstruction, talk to your health care team about the available treatments and your goals of care, because in most cases treatment relieves symptoms and improves quality of life but may not help you live longer from the cancer. It adds that you and your family may need to make difficult decisions at this time.

That is not a reason to do nothing. Relief of vomiting and pain is worth having on its own terms, and a venting tube or octreotide can buy real comfort without an operation.

But it does mean the honest question is not only "can this be cleared?" It is also "what am I trading, and for what?" Ask which option the team would choose for someone in your position, and why.

The obstruction itself is a same-day call. What changes the tier is a complication.

NCI describes a tear in the intestine letting fluid leak into the abdomen and causing sepsis. NHS puts confusion or slurred speech, breathing very fast, blue, pale or blotchy skin, a very high or very low temperature with shivering, or a rash that does not fade when pressed at the emergency level.

If any of those appear on top of a suspected blockage, that is the emergency number, not the clinic line.

Creating a Cancer Symptom and Call Plan, What to Have Ready for an Urgent Oncology Call, Preparing for an Emergency Department Visit With Cancer, and Sepsis During Cancer Treatment.

• National Cancer Institute — Bowel Obstruction and Cancer Treatment
• National Cancer Institute — Constipation and Cancer Treatment
• National Cancer Institute — Gastrointestinal Complications (PDQ) Health Professional Version
• MedlinePlus — Intestinal obstruction
• NHS — Sepsis