hi Sandy, Diastix measure glucose in the urine, so they're used by diabetics to see if their blood glucose is too high - though most diabetics check their blood directly these days. Ketostix are also used by diabetics to check that they haven't gone into ketoacidosis, which is dangerous for them. Ketostix measure ketones in the urine, which we also produce when we're burning fat. So - its Ketostix you want, not Diastix.
Also saw your question about psyllium - i'd say you probably do need to take that many capsules. I take the loose husks, three teaspoons in a glass of water - it takes some swallowing! It would take quite a few capsules to make upto three teaspoons I should think.
All the best, Jay