30th July 2023

A 57-year-old woman presents to her GP with a one-month history of watery diarrhoea and mild abdominal discomfort

A 57-year-old woman presents to her GP with a one-month history of watery diarrhoea and mild abdominal discomfort. She has a history of well-controlled hypothyroidism and psoriasis. Initial investigations, including coeliac screen and stool cultures, are negative.
She undergoes a colonoscopy which shows a normal macroscopic appearance of the bowel. Biopsies were also taken, and after histological evaluation, showed increased lymphocytic infiltration of the lamina propria.

What is the most likely diagnosis?

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