Hypothyroidism is one of the most common endocrine conditions encountered in the UK, and is more common in females than males (ratio 6:1). In one study, the prevalence of overt hypothyroidism was reported to be 9.3% in women and 1.3% in men, with an annual incidence of 40/10 000 and 6/10 000, respectively.1
It is usually primary, as a result of disease of the thyroid gland itself. The most common cause is autoimmunity, but other causes include iatrogenic (damage from surgery, radiation, radioiodine or drug treatment—for example, amiodarone, lithium and thalidomide), and iodine deficiency. Hypothyroidism due to hypothalamic–pituitary disease, resulting in low thyroid stimulating hormone (TSH, “secondary”) or thyrotropin releasing hormone (TRH, “tertiary”), is rare.
Hypothyroidism may manifest with a multitude of symptoms in adults, including fatigue, excessive somnolence, increased cold sensitivity, pale and dry skin, face puffiness, hoarse voice, unexplained weight gain, myalgia, bradycardia, arthralgia, muscle weakness, menorrhagia, brittle fingernails and hair, and depression. Constipation is the classical gastrointestinal symptom associated with hypothyroidism.
The diagnosis of hypothyroidism can be confirmed by carrying out thyroid function tests (TFTs), which are widely available. In primary hypothyroidism, thyroid stimulating hormone (TSH) values are raised and the total T4 (thyroxine) and free T3 (tri-iodothyronine) and are classically low. Further investigations can be considered in the presence of goitres or nodules, such as ultrasonographc scanning with targeted fine needle aspiration for histology/cytology.
A literature review revealed no similar cases in adults. No reports were found of abdominal pain, vomiting and diarrhoea being associated with hypothyroidism. Theoretically, these symptoms might occur in the presence of hypothyroidism associated severe constipation; however, our patient did not have evidence of this. In the absence of severe constipation, the mechanism by which hypothyroidism might cause abdominal pain, vomiting and diarrhoea is unclear. In the paediatric literature there have been reports of congenital hypothyroidism presenting with recurrent vomiting due to severe intestinal hypomotility.2,3
- Persistent nausea, vomiting, diarrhoea and abdominal pain can be caused by hypothyroidism.
- Hypothyroidism is a rare cause of these symptoms.
- Thyroid function tests should be conducted in patients with refractory gastrointestinal symptoms, especially if routine investigations do not reveal a cause.