I have been treated for trich with flagal the 1 day 4 pills and the 7 day 2 pills and it hasn't worked now they want to put me on tinidazole?

Resistance: Flagyl has been the main stay of treatment for so long, some resistance is developing. Tindamax is in the same family but has been used less so resistance is less likely and safer than just raising the dose of Flagyl to try to over come resistance.

Same as flagyl: i'm not certain the reason that the want to switch you to a drug that is basically the same but with a shorter duration of treatment. Listen to your doctors.