How to tell if there is a blockage?

This is actually regarding my dumeril's boa. I use sophresh aspen bedding that's thick and gross, and I know that Vigil has eaten a bit of it in the past (as it sticks to the rat while she's swallowing), but I assumed that she can digest it. Recently, I saw that consuming too much aspen can cause blockages. She hasn't pooped in longer than usual, and I'm just getting paranoid...

So I am wondering how I can tell/feel if there is a blockage that I should be worried about?

Hi,

Generally I look for bulges around the vent that grow larger but never move closer to the vent. Mostly it is fine but I'm not a boa guy so am unsure how often they tend to go.

Thanks- would the bulge be more stiff to the touch, or would it still feel normal?

When one of my retics was blocked up due to a colon infection, it felt very hard. She looked and felt like she'd swallowed a softball.

Just be aware, even in a non-constipated snake, you can still sometimes feel a hard ball in their tail, that's the urate. If the tail itself seems squishy when you press it, it's probably ok, but if the tail doesn't really give when press in from the bottom then that may be a sign of constipation. Just gently push at the belly, not too hard.

Eek... Where should I feel for it, above or below the vent?

Above the vent.