Caffeine and blood test question

[Tuxi1]

Odd question needing urgent answer!

Will it cause problems to my blood test results for thyroid and other things like liver etc if I have a double coffee just beforehand? I need to pass some stool (for a stool test before I go) and coffee usually helps with that. Probably won't be able to pass stool otherwise! Any ideas?

[SeasideSusie Remembering]

Tuxi1

It's recommended that only water is taken before a blood test, certain foods and some drinks can affect TSH.

This article suggests coffee interferes with blood test results:

healthline.com/health/fasti...

Can you drink coffee if you’re fasting before a blood test?

Even if you drink it black, coffee can interfere with blood test results. That’s because it contains caffeine and soluble plant matter, which might skew your test results.

Coffee is also a diuretic, which means that it will increase how much you pee. This can have a dehydrating effect. The less hydrated you are, the harder it can be for the nurse or other medical professional who’s doing your blood test to find a vein. This can make the blood test harder or more stressful for you.

Can you not take a stool sample into the surgery at another time, eg have coffee when you get back and then take sample in.

[Tuxi1 in reply to SeasideSusie]

Bit difficult as I have done one and need another ASAP and doctors takes 20mins to get to and I work. Maybe they will have to have one sample only!

[Tuxi1 in reply to Tuxi1]

Suppose had better not have the coffee!

[Anthea55]

Some foods help to make softer stools. I make sure I have sweet potato 2 or 3 times a week. Or try tinned prunes or tinned figs with breakfast.

[Tuxi1 in reply to Anthea55]

Sorry - can’t have any as allergic to most foods atm! Didn’t know that sweet potatoes make you go?!

[Anthea55 in reply to Tuxi1]

Sweet potatoes work for me. I don't know about anyone else.

[Anthea55 in reply to Tuxi1]

I started using sweet potatoes as I have several food intolerances, one of which is potato. However sweet potato is not one of the nightshades but from a different botanical family. Nightshades include things like tomatoes and peppers as well as potatoes - fortunately it's only potatoes that disagree with me so far.

Google for 'foods to soften stool' and you'll find other useful foods - including sweet potato.