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Causes, Symptoms & Treatments for Diarrhea

Diarrhea is characterised by unformed, watery stools and increased bowel movement frequency.

Diarrhea may be acute or chronic. Acute diarrhea is often due to infectious agents and is accompanied by fever, chills and malaise. Gastroenteritis is caused by infectious agents (bacteria, virus, parasite, protozoa etc.) from contaminated food, water or close contact with an infected person.  

Chronic diarrhea is defined by regular loose stools over a period of months or years. 

Causes of Diarrhea

  • Acute
  • Gastroenteritis
  • Antibiotic side-effects
  • Food poisoning
  • Anxiety/stress
  • Excessive alcohol or caffeine
  • Vitamin C or Mg overdose
  • Artificial sweeteners
  • Appendicitis
  • Acute infections (e.g. cholera, typhoid, malaria, amoebiasis)
  • Chronic: causes loss of nutrients and lowered vitality
  • Irritable bowel syndrome
  • Inflammatory bowel disease
  • Coeliac disease
  • Chronic bowel infection (e.g. Giardia)
  • Lactose intolerance
  • Food allergy
  • Diverticulitis
  • Hyperthyroidism
  • Pancreatic disease
  • Bowel carcinoma
  • Intussusception

Differential diagnosis

  • Small stool volume: inflammation
  • Large stool volume: laxative abuse and malabsorption (e.g. coeliac)
  • Profuse bright red blood: diverticulitis
  • Black tarry stools: carcinoma
  • Mucous, pus, blood in stool: inflammatory bowel disease
  • Pale fatty offensive stool that floats : indicates malabsorption
  • Watery offensive bubbly stools: Giardia lamblia
  • Pellets or ribbons: IBS, carcinoma
  • Diarrhea after travelling overseas: parasitic infection
  • Fever: infection
  • Family history: coeliac disease, lactose intolerance
  • Clammy, shaky, rapid heartbeat, weight loss: hyperthyroidism


  • Advanced stool analysis – microbes, malabsorption, presence of blood
  • Comprehensive blood panel inc. iron studies and thyroid function test
  • Celiac screening
  • Endoscopy/colonoscopy
  • SIBO breath test


Acute diarrhea / gastroenteritis (never suppress symptoms)

NB. Severe acute diarrhea can be life-threatening – if patient is no better after 24 hours, patient should seek acute medical care.

  • Rest
  • Rehydrate – fluids and electrolytes
  • Convalescent diet / fasting
  • Eradicate pathogenic organisms
  • Tone bowel wall
  • Support bowel microflora

Chronic diarrhea

  • Identify / address underlying cause

Diet plan guidelines that support Acute Diarrhea

  • Fasting (except for fluids) during acute phase is recommended
  • Maintain fluids and replace electrolytes:
  • Oral glucose electrolyte solution
  • Dilute fruit and vegetable juices
  • Add ½ tsp salt, ¼ tsp bicarbonate soda, ¼ tsp potassium chloride, 2 Tbsp glucose (or honey) to 1L water. Mix with peppermint, fennel, chamomile and/or ginger tea and sip slowly
  • Rice /barley water: boil ½ cup brown rice or barley in 3 cups water for 45 minutes – drink the water and eat the grain – helps to form stools and replace B-vitamins
  • Herbal teas: peppermint, ginger, black tea
  • Apple pectin can help counteract bacteria that cause diarrhea and also helps soothe irritated intestinal walls. May be taken as grated raw apple, fresh apple juice or apple sauce every 2-4 hours as tolerated
  • Once acute stage is over, a convalescent diet may be instituted: clear soups (miso, chicken), white rice, grated apple, bananas, natural yoghurt
  • Avoid protein, dairy, coffee, chocolate, strong spices, excessive fibre

Supplements that support Diarrhea

  • Probiotics: Saccharomyces boulardii, Lactobacillus rhamnosus GG and Lactobacillus acidophilus have been shown to be effective in antibiotic-induced and infectious diarrhea.  Other soil based probiotics have also shown to be effective.
  • Zinc: decreases severity and duration
  • Garlic supplement: broad-spectrum antimicrobial
  • Glutamine: Caused by mucosal irritation
  • Vitamin C: immune support in infectious diarrhea

Herbal medicine treatment

  • Antimicrobials: barberry, goldenseal, chamomile, oregano, thyme, yarrow
  • Anti-diarrhea / astringent: cranesbill, cinnamon, raspberry leaf, shatavari, black haw, meadowsweet, shepherd’s purse
  • Antispasmodics / carminatives: chamomile, peppermint, fennel, cinnamon, ginger
  • Demulcents (once acute stage is over to help soothe and heal bowel wall): slippery elm, marshmallow, licorice


The above considerations  may assist in the relief such symptoms. 

To reverse chronic diarrhea, the underlying cause must be uncovered and treated.  At our Perth clinic of Advanced Functional Medicine we have experience with such chronic issues

Thorough investigation is required to identify underlying triggers.  Parasites, bacterial infections, gut dysbiosis, food intolerances, mineral deficiencies and IBS are all contributing factors that we uncover through our advanced testing.

Specific individualised treatment along with diet recommendations is required to return stools to a normal consistency and frequency.  

If you or a family member are require assistance with chronic diarrhea or other digestive disorder we would love to hear from you.  Did you find parasites of bacterial pathogens in your stool sample that were causing it?  Were food intolerances your main driving factor?  Please write a comment below.

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The above information is intended to be general, educational advice only, on topics which are of interest to us. It is not intended to represent specific or individual health or medical advice and is not specific to your situation. The below information is educative and is not intended to advertise any service.

Before making any decisions in relation to your health, you should always discuss your individual situation with your own health practitioners to ensure that any advice you have read is right for you.

Jarrod Cooper – ND

Jarrod Cooper – ND

Jarrod Cooper - ND is the founder of Advanced Functional Medicine Australia. He is a Naturopathic Doctor with extensive functional medicine training from leading practitioners in the USA and worldwide.

He is leading the way with advancements of functional medicine, clinically implementing worldwide best practices in Functional Medicine throughout Australia.

Jarrod consults in person from Perth, Western Australia and also online via Telehealth throughout Australia and worldwide.

If you are looking for personalised treatment, we highly recommend contacting Jarrod Cooper’s Advanced Functional Medicine clinic in Australia.

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