Differentiating the causes of weight loss, diarrhoea. Another case another disease.

A 23 year old woman presented to the OPD of her hospital with palpitation. Her description was “My heart thuds so fast that I think it is going to burst. It drums in my ear, goes fast and sometimes slower and takes hours to settle to a steady beat after I have rested for hours, had some water and something to eat and sometimes I have to go to a doctor who gives me some tablets and oxygen to inhale in his clinic I get dizzy and breathless. Sometimes I cough a lot and bring up phlegm tinged with blood. My heart always beats faster than when I was well all the time and goes fast and slow.”

When were you well and what symptoms did you have to begin with before the palpitation began?

She had developed diarrhoea six months ago. She passed 3-6 semi-formed stools a day without mucus or blood. She had a good appetite. had no abdominal cramps and has lost 6 kg weight during this time. She has no fever, night sweats, abdominal bloating, heartburn or rectal discomfort on passing stool. She did not pass urine in excess nor feel unduly thirsty. She lived with her husband who was healthy, her mother in law who had been treated for pulmonary tuberculosis a year back and was now in good health and was asymptomatic. Her two year old son and 5 year old daughter had received BCG vaccination as part of their childhood vaccination program and were in apparent good health. Her husband was the breadwinner. He was a carpenter, rented a comfortable house with electricity and running water and the family ate meat, chicken, vegetables, fruit and dal daily and had access to a government hospital in a nearby town.

What do we need to learn more about the diarrhoea? We know the frequency and consistency and that there is no blood or mucus so is unlikely to be from the large gut or an infection. Is the diarrhoea infective, inflammatory in nature or non-inflammatory? Is it secretory or osmotic or malabsorptive in character? There is no fever, night sweats, abdominal pain or colic. She does not complain of proctitis i.e. pain during defecation and does not give symptoms suggestive of anorectal fistula or abscess so the diarrhoea is non-inflammatory most probably. Type 1 diabetes, hyperthyroidism, other metabolic causes of diarrhoea, malabsorption, adult celiac disease?

Characterisation of diarrhoea.

  • Watery diarrhea – The water content of chronic diarrhea can be caused by secretory or osmotic processes, or a combination of the two. Measure fecal electrolytes, pH, reducing substances and calculate the osmotic gap.
  • Secretory diarrhoea occurs in cholera and carcinoid. It is large in volume and persists on fasting.
  • Osmotic – Osmotic (or “substrate-induced” or “diet-related” or overeating) diarrhea typically is less voluminous than secretory diarrhea (eg, <200 mL per day), and improves or resolves during 12- to 24-hours of fasting. The presence of reducing substances or low fecal pH (ie, pH <6) suggest carbohydrate malabsorption.
  • Fatty diarrhea – Malabsorption is often accompanied by steatorrhea and the passage of bulky malodorous pale stools.
  • Inflammatory diarrhea – Inflammatory forms of diarrhea typically present with liquid loose stools with blood. Elevation in fecal calprotectin (a protein found in neutrophil granulocytes) indicates an inflammatory diarrhea.

You need to ask the appropriate questions to elicit this information even if you have noticed the goitre in your observation.

She has no symptoms suggestive of diabetes like polyuria, polydipsia and polyphagia but fewer than 30% have these symptoms so don’t rely on them. Check out her fasting blood sugar and HbA1c.

The problem is solved when you examine her. The pulse is 110/min, irregular; she is afebrile; BP is 110/70 mmHg; her thyroid is diffusely enlarged with no bruit or cystic feel to it; she has lidlag but no prominent proptosis and is not in heart failure nor does she have a valve lesion; there is a fine tremor in the outstretched hands. The diarrhoea is caused by hyperthyroidism.

The problems you will have to sort out and be asked about are

  • How to handle her AF; whether to anticoagulate or not; rate control or rhythm control; what rate to keep her pulse at.
  • What treatment is best for he to control her hyperthyroidism; pros and cons of propylthiouracil and its indications; how long to treat; use of beta blocker; when to prescribe radio iodine; what to do in pregnancy; teratogenic effects of the different drugs.
  • How to treat the diarrhoea.
  • How to treat the tremors.
  • How to get her weight up.
  • What is the pathophysiology behind the symptoms.
  • How to investigate her.
  • Interpretation of the tests.
  • What to do if she gets pregnant.
  • Diagnosis and treatment of a thyroid crisis.
  • How to treat proptosis.
  • What are the surgical options for Graves ophthalmopathy.
  • What is the response time and how to monitor the patient.
  • What is the relapse rate.

I will leave you to find out the answers and then you will be well prepared for a viva.

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I am a Professor of Medicine and a Nephrologist. Having served in the Army Medical College, Pakistan Army for 27 years I eventually became the Dean and Principal of the Bahria University Medical and Dental College Karachi from where I retired in 2016. My passion is teaching and mentoring young doctors. I am associated with the College of Physicians and Surgeons Pakistan as a Fellow and an examiner. I find that many young doctors make mistakes because they do not understand how they should answer questions; basically they do not understand why a question is being asked. My aim is to help them process the information they acquire as part of their education to answer questions, pass examinations and to best take care of patients without supervision of a consultant. Read my blog, interact and ask questions so that I can help you more.

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