Approaches to Diarrhoea

In this episode of PodMD, experienced gastroenterologist and educator A/Prof Mark Ward will be discussing the topic of approaches to diarrhoea, including what diarrhoea is, the common causes, when a GP should refer and more.

  • Transcript
    Please note this is a machine generated transcription and may contain some errors.
    *As always, all in this PODMD podcast is intended for health professionals and the comments are of a general nature. Information given is not intended as specific medical advice pertaining to any given patient. If you have a clinical issue with one of your patients please seek appropriate advice from a colleague with expertise in the area.

    Today I’d like to welcome to the PodMd studio Gastroenterologist, Associate Professor Mark Ward.

    Mark Ward is an experienced gastroenterologist and educator based in Melbourne; he holds appointments at the Alfred Hospital and as an Associate Professor at Monash University. Mark’s private practice is in Glen Iris and South Melbourne. Mark has a particular interest in inflammatory bowel disease and is a current member on the Australian IBD Faculty Executive Committee.

    Today, we’ll be discussing approaches to diarrhoea.

    *We do hope you enjoy this podcast but please remember that the advice here is of a general nature and is not intended as specific advice about a given patient. The views and opinions expressed in this podcast are those of the doctor, not PodMD.
    If you do have a patient on whom you require specific advice, then please seek advice from a colleague with appropriate expertise in that area.

    Mark, thanks for talking with us on Pod MD today.

    Mark: Thanks very much for having me

    Question 1
    The topic of today’s discussion is diarrhoea, can you describe for our listeners what diarrhoea is?

    Mark: I’m really happy you’ve actually asked me that because diarrhea is a common symptom, but it means different things to different people and to patients. We think of diarrhea in its simplest form as just being increased stool frequency, but a lot of patients are confused by this and they actually refer to diarrhea as being a normal frequency, but just being a loose consistency. It can mean two different things. And then in my mind, when I think about diarrhea, I think about whether it’s acute or chronic and chronic is defined as greater than four weeks of symptoms. That’s also worth putting into context that patient’s socioeconomic background, so patients from lower socioeconomic backgrounds, including those in developing countries will have significantly different, uh, causes of diarrhea compared to, um, patients that you would expect to see, um, within Australia.

    Question 2
    How would a patient with diarrhoea typically present?

    Mark: There are lots of different ways that they might present, and the types of things that I like to ask patients are; ask them to describe the diarrhea. Is it actually a watery diarrhea that we all are familiar with if we’ve had an effective gastroenteritis, often it’s not. And I use the Bristol stool chart and often patients diary they mean a semi formed or loose stool. I want to know how long the symptoms have been present for, do they have alarm symptoms or red flag features that I’ll touch on later. And then I always ask, is there incontinence, because patients often describe diarrhea as actually having fecal incontinence. So they might have accidents and they call this diarrhea when actually it’s not diarrhea per se. I always ask about whether there’s a bleeding, which would suggest a lower GI source in the colon rather than small intestine. Are there features of steatorrhea. So the stool that the patient will try and flush over and over again, and they can’t flush away, which might suggest a malabsorptive process. What risk factors they might have, travel, social, history of sexually transmitted infections. Do they have systemic features like fevers or weight loss, inflammatory symptoms involving parts outside the gut, like the eyes or the skin and the joints. And then I take a brief mental, assess their mental state for anxiety and depression because, coexisting mental health issues are common in patients with functional abdominal problems and diarrhea.

    Question 3
    What are common causes of chronic diarrhoea?

    Mark: By far and away the most common cause of chronic diarrhea in general practice and in a gastroenterologist practice is irritable bowel syndrome, diarrhea predominant, and that’s really a diagnosis of exclusion, some less common causes, but that we still see frequently are inflammatory bowel disease, post cholecystectomy state, issues with bile salt diarrhea, and microscopic colitis, hypothyroidism, although that normally doesn’t get to the gastroenterologist, malignancy, Coeliac Disease and then some less common causes such as chronic infections, particularly Chiaradia, medications, antibiotics especially macrolides, anti-inflammatory tablets, olmesartan and magnesium hypoglycemic medications like Metformin, small intestinal, bacterial overgrowth, and poorly controlled diabetes. And then the rare, the rare stuff down the bottom, small bowel enteropathy, hyperparathyroidism, autonomic neuropathy, factitious, diarrhea, hormones secreting cancers and Addison’s disease.

    Question 4
    How should a patient be evaluated or investigated?

    Mark: I think in family practice after a good history and examination patients should undergo routine blood testing, which includes a CRP or ESR, thyroid function testing and coeliac serology stool based testing to look for infectious causes, calcium, magnesium and phosphate. And then I think beyond that, the most important test to consider doing is a fecal calprotectin, which is a non-invasive stool-based marker of intestinal inflammation, which should be getting onto a Medicare rebate over the next six to 12 months. But before that typically is an out of pocket cost of about $50 to $80, it’s a really valuable test to look for inflammatory causes of diarrhea. If the patient’s in an at risk group, a fecal occult blood test. And then some of the other things that I would be using more regularly would be imaging such as intestinal ultrasound or cross-sectional imaging where appropriate gastroscopy and colonoscopy. And if I suspect a malabsorptive state with steatorrhea, I’ll run off a fecal elastase keeping in mind that there is a significant out-of-pocket cost for the patient for that test.

    Question 5
    Are there any warning signs a GP or their patient can look out for?

    Mark: Absolutely. Overt GI bleeding shouldn’t be disregarded, so Hematochezia or Molina. Somebody who’s got new onset abdominal symptoms diarrhea after the age of 50 is a concern. If there’s nocturnal diarrhea that suggests an inflammatory cause. Patients with functional gut disorders and irritable bowel syndrome, they don’t usually wake up overnight, but those were the inflammation can, I think abdominal pain, which is not such a non-specific symptom, that pain that is progressive and unrelenting warrants, further investigation, unexplained weight loss, systemic features like fever, a really strong family history, for example, a first degree relative that has IBD or colorectal cancer. And then if you’ve done some tests and there’s objective evidence of inflammation or bleeding such as raised inflammatory markers anemia, hypoalbuminemia, a fecal calprotectin or fecal occult blood test that’s abnormal, they should all be referred on.

    Question 6
    When should a GP refer?

    Mark: With any of those alarm symptoms, and I think also patients that you think you’ve worked up and you feel do you have irritable bowel syndrome, diarrhea predominant, and you’ve tried first-line treatments such as dietary intervention or fiber supplement and haven’t gotten better, they should be referred as well.

    Question 7
    You touched on Irritable Bowel Syndrome being a common cause of diarrhoea, can you tell us your approach to management?

    Mark: Yeah, thanks for asking. It is a common cause. And so once I’m comfortable with the diagnosis, the first thing is to discuss with the patient, you give them education and reassure them that their diarrhea and their symptoms aren’t causing damage. It’s just the effect on their quality of life. And therefore, depending on how the magnitude of that effect sort of dictates how hard we’re going to push treatment. I then put patients onto a low FODMAP diet. I tell them that this reduces diarrhea and about 60 to 70% of patients with IBS. And I encourage them to do that either by downloading the Monash low-FODMAP diet app or using other internet resources or referring them to a dietician. Tell them that a patient’s on a low FODMAP diet persevere for four weeks and then the rechallenge phase is really important. And also when going into a low FODMAP diet, a fiber supplement is important too. That’s how I manage first line, in second line, I might use something such as Rifaximin, which is an antibiotic, it’s had really good placebo controlled evidence in this setting. It’s not on the PBS. So it has to be compounded, typically costs about 80 to a hundred dollars for a two week course. It’s really, really safe. It’s a two week course and improves diarrhoea in a large proportion of patients.

    Question 8
    What role does the GP play in the treatment of the condition?

    Mark: Well, I think that most GPS in the absence of red flag symptoms are comfortable diagnosing irritable bowel syndrome, diarrhea, predominant. And so they can do those first two lines of management that I would normally do, engage a dietician or talk to a patient about low FODMAP diet and then GPS, I would encourage them to also use Rifaximin or become comfortable using it. And then, I think also because irritable bowel syndrome diarrhea prominent is so common and gastroenterologists see it so frequently. I really want to hear from my GPS if they know their patients better than I do and they’re worried that there are other symptoms that I haven’t teased out and they are concerned there might be more occult pathology and need more investigations such as with an endoscopy or with imaging.

    Concluding Question
    Thank you for your time here today in the PodMD studio. To sum up for us, could you please identify the three key take home messages from today’s podcast on a Coeliasc Disease?

    1. The first one is that diarrhea is a really, really common symptom and presentation and clarifying with the patient, what they mean by diarrhea can be helpful and it can exclude other issues like fecal incontinence or problems with loading.
    2. The second one is to be familiar or aware of red flag symptoms and know when to refer on.
    3. And the third is that most diarrhea in the absence of red flag symptoms is due to irritable bowel syndrome and that the vast majority will improve on a low FODMAP diet or failing that the use of Rifaximin.

    Thanks for your time and the insights you’ve provided.

    Mark: Thank you very much for having me.

*As always, all in this PODMD podcast is intended for health professionals and the comments are of a general nature. Information given is not intended as specific medical advice pertaining to any given patient. If you have a clinical issue with one of your patients please seek appropriate advice from a colleague with expertise in the area.