Could my diarrhea be caused by a carcinoid tumor?

November 12, 2012

Could my diarrhea be caused by a carcinoid tumor?

Very rarely some cancers may result in the patient experiencing bouts of diarrhea. These include -

  • Any malignant tumor that has metastasized into an abdominal organ

  • Tumors, such as carcinoid tumors, which produce excess hormones resulting in carcinoid syndrome, which produces excessive amounts of serotonin or Zollinger-Ellison syndrome – the result of large amounts of gastrin being secreted by pancreatic or duodenal cancers.

  • Colorectal cancer

  • Intestinal lymphoma

  • Medullar cancer of the thyroid gland

  • Pancreatic cancer

  • Gall bladder and bile duct cancer

  • Hepatocellular cancer

Abdominal cancers

Most cancers which occur in the organs of the abdomen cause few symptoms until the disease is well advanced and diarrhea may not be one of them – patients with colorectal cancer are more likely to experience constipation than diarrhea.

When a cancer patient is suffering with bouts of diarrhea as a result of the disease narcotics, such as codeine and anti-diarrheal drugs such as loperamide may be prescribed.

Carcinoid tumors

Carcinoid tumors are slow growing tumors which are quite uncommon. These tumors are generally found in patients who are over fifty years of age and affect the abdominal organs such as the small intestine, appendix, colon, stomach, pancreas, liver or the lungs.

Carcinoid tumors cause an excessive amount of the hormone serotonin to be secreted. This hormone may cause arteries to dilate and the bronchi to spasm causing symptoms such as the following -

  • Flushing – not sweating, dry flushing which the patient may not even notice – which may be followed by bluish skin spots known as cyanosis.

  • Heart palpitations

  • Low blood pressure

  • Abdominal cramping and diarrhea

  • Spider veins

  • Swelling of limbs

  • Wheezing and shortness of breath

These symptoms are generally referred to as carcinoid syndrome.


When carcinoid tumors cause a severe episode of these associated symptoms, referred to as a carcinoid crisis, this is usually due to the original carcinoid tumor metastasizing to the liver. A carcinoid crisis may be caused by stress, certain foods, alcohol or have no apparent cause, these episodes are rarely fatal. The liver is able to secrete excess serotonin produced by the tumor into the systemic bloodstream – however if a tumor begins to grow within the liver it will no longer be able to process the serotonin.

Generally speaking

Diarrhea may well be a symptom of the carcinoid syndrome, if so it will develop very quickly after eating and will be accompanied by the dry flushing effect around the face and chest.

Blood and urine tests are used to diagnose carcinoid tumors, these tests measure serotonin levels and may be followed by imaging tests and investigations in order to locate the tumors.


When carcinoid develops in children it is generally in the appendix – consequently an appendectomy will usually affect a complete cure.

Surgery is usually the first treatment option for adults and is usually successful in the early stages of the disease when it is possible to remove the entire tumor.

Chemotherapy, medication, radiation may also be used in conjunction with surgery or, if surgery is no longer possible, will be administered appropriately.

If the tumor is completely removed and symptoms are not yet severe the prognosis for carcinoid patients is good.


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