Heartburn and diarrhoea - what was the cause in this case

In this month’s case, Dr Nazeli Manukyan asked readers to suggest what was causing persistent heartburn in this female patient. Answer revealed below!

Note that details of the case have been altered to protect individuals’ identities

A 39-year-old female initially presented to the GP practice with reported episodes of diarrhoea and persistent heartburn.

Blood tests showed normal FBC, CRP, ESR, negative coeliac screen, negative stool culture and normal faecal calprotectin. The patient failed to respond to different proton pump inhibitors (PPIs) – omeprazole, pantoprazole and esomeprazole at high doses – and to metoclopramide.

The patient was referred to Gastroenterology for investigations which revealed normal gastroscopy, negative H.pylori, normal ultrasound and normal 24-hour oesophageal pH studies.

A follow-up gastroscopy was planned by the Gastroenterology team. It was at this point, around 18 months after her referral, that I met the patient for the first time. The patient did not report any other symptoms apart from ongoing bothersome heartburn episodes.

What do you think was going on? What other investigations did the patient require?

Answer: As described above, the patient did not report other symptoms at this time, but it was evident that she was clinically thyrotoxic. She had an apparent goitre, fine tremor, palmar erythema, facial flushing, mild lagophthalmos and sinus tachycardia (120bpm).

Blood tests confirmed biochemical hyperthyroidism, with TSH <0.01, T4 46.9 and positive thyroid receptor antibody levels.

The patient improved with carbimazole and beta blockers and was referred to an endocrinologist. Her dyspepsia responded very well when she became euthyroid.

The key learning point is that dyspepsia and increased gut motility can be the main presentation of hyperthyroidism, so it is important to explore potential thyrotoxicosis and consider thyroid testing in patients with these symptoms. While dyspepsia is not the most common presentation of thyrotoxicosis, it is a recognised manifestation and should be considered in the differential diagnosis, especially when accompanied by other signs of hyperthyroidism.

Thyrotoxicosis is thought to contribute to dyspepsia through a combination of autonomic dysfunction, which can affect gut motility, accelerated gastric emptying and intestinal transit, and reduced gastric acid production, partly due to autoimmune gastritis, which impairs digestion.

In this case the patient was seeing different GPs at the practice each time, so had not had consistent follow up, and had not been tested in secondary care. It is likely that after the initial referral, she was not examined again while undergoing investigations.

Dr Nazeli Manukyan is a GP based in Surrey

Sources

Xu G-M et al. Thyroid disorders and gastrointestinal motility: an old association. Front Physiol 2024;15:1389113
Ebert E. The thyroid and the gut. J Clin Gastroenterol 2010;44(6):402-6
Evsyutina Y et al. Case report of Graves’ disease manifesting with odynophagia and heartburn. World J Gastroenterol 2015 Dec 28;21(48):13582-6
Ross D et al. 2016 American Thyroid Association Guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Thyroid 2016 Oct;26(10):1343-1421

For more diagnostic puzzles, see previous articles in our Case of the month series:

Have you handled a case which had a slightly surprising outcome? Perhaps an elderly man with non-vertigo dizziness? Or an unexpected cause of bradycardia? Would you like to share your case studies with us to help support and inform GPs? Please get in touch if you would like to contribute! [email protected]