Annette Bisanz, MPH, RN
Advanced Practice
Nurse
Nursing Administration
The University of Texas, MD
Anderson Cancer Center
Hello. My name is Annette Bisanz. And today we're going to discuss diarrhea and its multiple causes.
The objectives for this partic --- this session is that all participants will be able to: assess for multiple causes of diarrhea; include all causative factors in the patient's treatment plan; and discuss the use of the Diarrhea Assessment and Treatment Tool, named the DATT.
The NCI definitions for diarrhea are, using a grading system: Mild diarrhea, Grade 1: 2-3 stools above normal per day; Mild to Moderate: 4 to 6 stools above normal per day, or Grade 2; Moderate Sev --- to Severe: 7 to 9 stools above normal, with possibly severe cramps and in --- incontinence; and Grade 4 is Severe: 10 or more stools above normal, and the patient may have bloody diarrhea.
The clinical definition of diarrhea that I think is important is if the patient has more than 3 loose stools per day. It's very important in treating diarrhea that we understand the volume or the amount of liquid that the patient is excreting in the stool. And --- And that's --- that's one of the things that sometimes we lack in our clinical practice. And so I challenge people to look at the volume, not so much as the number of times, because each stool, one could be 25 cc., one could be 100 cc., one could be 1000 cc., so we need to really focus more in our clinical practice on the volume of the amount of diarrhea that the patient is having.
There are different classifications of diarrhea. There's secretory diarrhea, osmotic diarrhea, exudative, malabsorptive, and dysmotility.
The mechanisms of diarrhea are: a decreased absorption of fluid and electrolytes, which normally are reabsorbed back into the system through the --- the wall of the intestine; and the other is increased secretion of fluid and electrolytes into the col --- into the GI tract.
So if you look at this diagram, you'll see the left-hand arrow there, that things are just kind of moving through the GI tract, maybe very fast. There's not the absorption that normally should be taking place back into the system taking place. There's a defective absorption then, and osmotically active agents in the lumen can definitely increase the GI motility. If you look at the arrow on the right, there's increased secretion from the wall of the intestine, and there's fluid and electrolytes pouring into the GI tract faster than the GI tract can handle it. And this can be caused from endogenous secretagogues or exogenous toxins. And so it's important to realize that the patient could have one or both of these mechanisms going on at the same time, depending on the kind of diarrhea, or the multiple types of diarrhea that the patient is having.
Let's first talk about secretory diarrhea. Secretory diarrhea is characterized by an increased secretion of fluids and electrolytes. It interferes with the digestive enzymes, so the food isn't metabolized appropriately, and there's damage of the intestinal mucosa and increased GI motility. It's associated with neuroendocrine tumors, VIPomas, gastrinomas, carcinoid syndrome, secretory adenomas, and interstitial --- intestinal inflammation as in C. difficile.
Secretory diarrhea persists even when the patient is fasting. It produces large volumes of stool, usually more than 1 liter per day. It produces negative pathology reports. You won't find that there's other organisms in the stool. And it occurs in patients with a carcinoid tumor along with symptoms of flushing, hypotension, vasodilation, and bronchoconstriction.
Chemotherapy induced diarrhea is also considered a secretory type of diarrhea because it --- it secretes a lot of fluid into the intestine and it's characterized by an imbalance between the absorption and the secretion in the small bowel. And there's damage to the intestinal mucosa, and there can be a bacterial overgrowth and opportunistic infections occurring due to the myelosuppression of the patient. It's associated with antimetabolite chemotherapies, a combination of chemotherapeutic agents and biologic response modifiers. Dosing schedules can make a difference in the amount of diarrhea the patient has. And cytoprotectants like Mesna can cause diarrhea.
The common anti-cancer agents associated with diarrhea are: irinotecan, 5-FU/Leucovorin, high-dose cisplatin, oxaliplatin, paclitaxel, cyclophosphamide, topotecan, methotrexate, nitrosureas, cytosine arabinoside, doxorubicin, daunorubicin, hydroxyurea, thioguanine, 5-azacitidine, and biotherapy, including interleukins and interferons.
Let's now go to osmotic type of diarrhea. Osmotic type of diarrhea is characterized by ingestion of an oral solute that's not fully absorbed. There's a rapid transit and a decreased exposure of the --- to the luminal contents to the intestinal wall so that absorb --- reabsorption is not taking place. This is associated with ingestion of nonabsorbable or hyperosmolar substances. It could possibly be an enteral feeding that is too hyperosmolar and the GI tract just cannot tolerate it. It also could be sorbitol-based liquid medication, and a lot of people are not aware of that. If they're taking strictly liquid medication, it may be sorbitol based, and that's sugar, and they are having problems with that, or sugar-free products can also cause an osmotic type of diarrhea.
In osmotic diarrhea, the stool volumes are less than 1 liter per day and the stools decrease if the patient is fasting. Sodium and potassium in the stool is not altered like it is with the secretory diarrhea.
Now let's go to exudative diarrhea. Exudative diarrhea is characterized by intestinal damage, inflammation, and a re --- release of prostaglandin. It's associated with radiation colitis and infections.
Exudative diarrhea results from mucosal damage and causes decreased amount of functional mucosa. And if you think of a person after radiation, the GI tract can be almost raw, and so anything that is raw will weep. And so that gives you an idea of how exudative diarrhea is affecting the GI tract. And there is usually a release of prostaglandin as a result of the intestinal damage and inflammation. Common treatment is a prostaglandin inhibitor. And interestingly enough, a prostaglandin inhibitor is aspirin and ibuprofen. In clinical practice, this is seldom used in oncology because we say, "While our patients are myelosuppressed, we don't want to give them aspirin. You know their platelets may be down" or "maybe they're on anticoagulant medications." But we meed --- need to be innovative, and if we understand the causative factor of the diarrhea, if they --- they need an antiprostaglandin, why not use aspirin and ibuprofen? All patients are not myelosuppressed and on anticoagulants.
Radiation induced diarrhea is ex --- an exudative type of diarrhea and it's secondary to acute enteritis and colitis. There is a partial villi atrophy and fibrosis making the lining in the --- the GI tract slick. There is impairment of bile acid absorption if the ileum is involved, and there is --- there can be bacterial overgrowth and chronic inflammation, nuclear atypia, epithelial flattening, and cell degradation when the patient has this type of diarrhea.
Then there's malabsorptive diarrhea. This is characterized by a disease resulting in malabsorption of solutes. There's --- There may be a lack of pancreatic enzymes, for example, in patients who have had a pancreatectomy. And the patient may be having an intolerance to gluten. This is associated with lactose intolerance, for example. And many of our patients develop lactose intolerance after many years being able to tolerate milk and milk products. And so this needs to be addressed and assessed in each of our patients. After a GI resection, the patient's going to have malabsorption because part of their GI tract may be missing, and especially if the pancreas is missing, they miss the --- the enzymes to digest fats. And then in celiac sprue, the patient cannot metabolize gluten; and gluten is in wheat products, barley, rye, and sometimes oats. And so this is a very important thing to assess your patients for.
Okay, then you have your dysmotility associated diarrhea. This is characterized by dysfunctional intestinal motility. It's associated with colorectal resection. Most of the people, after colorectal resection, have not a diarrhea, but a frequent soft, formed stool in very small amounts. This is not really a diarrhea, but the frequent stooling is very disconcerting, and many of these people have to stay near the bathroom. They'll have 15 to 30 stools per day. We do have treatment for that and we will discuss that. Post gastrectomy, they --- they will have a dysmotility-associated diarrhea. Also after an ileocecal valve resection, narcotic withdrawal, inflammatory conditions like irritable bowel syndrome, and drugs affecting peristalsis. And the one thing I think we don't think about is, the patient is nauseated and we are giving them Reglan® for nausea, metoclopramide. This will increase the GI motility and it can also enhance diarrhea.
Diarrhea has many causes. And so what we need to do is assess the current diarrhea treatment based on the causative factors for our patients. And remember, if a patient has diarrhea, all causes have to be treated for the diarrhea to go away.
So we need a comprehensive approach to assessing diarrhea. We need to have a way to organize our thought process so we don't forget different types of diarrheas that could be existing in our patients, and provide a guide for initial treatment. And so what we did is develop a Diarrhea Assessment and Treatment Tool, called the DATT, simply. And This provides guidance in addressing all causative factors in diarrhea so that all of them can be addressed.
In this next slide there are two pages. And I -- I would just like to discuss this with you and what this tool can do. This diarrhea assessment and treatment tool begins by getting a history of the patient's diarrhea and finding out exactly how long it has existed; what kind of cancer treatments the patient is on; how does the patient eat; does the patient aggravate his diarrhea by the kinds of foods that he eats; and what's the --- the patient's fluid intake and output per day; and what are the types of stools that the patient's having; the laboratory results that have been already addressed to see what the causative factors are of the diarrhea; and the medications that have already been tried that have not been successful. And then from there, after questioning the patient on all the causative factors of the different types of diarrhea, we begin to identify that the patient maybe has more than one type of diarrhea, more than one causative factor causing diarrhea. So once that's identified, then we can begin to look at a treatment program that addresses the entire spectrum of causative factors of diarrhea. And so on the second page, we worked with the Pharm.D.s here to help us in establishing an initial treatment for the various causative types of diarrhea. And these are listed on this sheet. What we have found is that it's very helpful in organizing your thought processes, not forgetting anything that could be causing the diarrhea, and if all of the types of diarrhea are addressed, you have a much better chance of getting effective treatment for your patient and the diarrhea will subside.
In summary, you have learned: how to fully assess patients for all causative factors of diarrhea; you've learned the importance of treating all causes to eliminate the diarrhea symptoms; and you've learned how to use the Diarrhea Assessment and Treatment tool to enhance your assessment of diarrhea. Thank you for your attention.
Diarrhea and its Multiple Causes video
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