Can HDT (B1) cause diarrhoea?

[Rafiki2]

My wife has been taking high doses of B1 for almost 2 months. She started with 1000mg per day, then went onto 1200mg and for the past 2 weeks has been taking 1400mg per day.

For the past 4 or 5 days she has been experiencing diarrhoea and at first we thought it was probably a bug but if this was the case, it should have stopped by now but it hasn't.

Having done further research, I came across a web site ( nhs.uk/medicines/thiamine-v... ) which mentions that one of the possible side effects of Thiamine (B1) can be diarrhoea. Out of well over a dozen other websites (including the Mayo Clinic) it is the only one that mentions this possible side effect.

Has anyone else taking HDT experienced diarrhoea, or have any information? I am reluctant to change her current dose as I think it is helping with the other symptoms and also because we would like to try the latest dose of 1400mg for a further couple of weeks before considering any changes.

Thanks