Psyllium/Plantago Ovata

Where can I buy it in Udon or in Thailand?

Ray, I've seen it somewhere but can't remember where. Check the various pharmacies around town. I saw an Asian clone of Metamucil somewhere. I only remember it because the label looked just like Metamucil, but didn't pay much attention to it since I wasn't in the market for it.

A visiting friend of ours needed some.....took him to the pharmacy on Makkaeng, between Phosri and Srisuk. As you're heading from Phosri, it's on the left hand side, about half way up. The girl there speaks English.

Thanks guys.
With that lead, I went to my regular pharmacy near Ban Hoy market, and got some. They were 4.5 baht for regular, and 6 baht for the sugar-free variety per single-use pack, brand name Mucilin; in the Staes it is branded Metamucil, I think. Next, I would try to find a place where I can buy it in bulk.
By the way, the stuff is not just for constipation, it is medically recommended for lowering cholesterol, as well. Throw some in the dough if you are baking. Cereals in the U.S. that claim to lower cholesterol contain it. There are not yet proven claims of lowering glucose level also. Check out Wiki for psylliam for more.