I'm 36. lately stool looks different every day... no blood but some days it's smaller, shorter, thinner and other days longer or thicker. sometimes feel like i didn't empty out fully. happens usually when i'm going through anxiety. causes?

Stool shape and color often has to do with dietary intake. Different substances in the diet will cause stool alterations-including color and shape/size. If you continue to feel like you are not emptying, you should see a GI doctor to get an evaluation to be certain this is not an issue. If it is due to constipation, after a complete evaluation, a treatment can be pursued. You may need colonoscopy.