How do I know if it's impaction versus normal floating?

Occasional brief floating is normal axolotl behaviour. Persistent floating combined with a visibly swollen belly and known access to gravel or small decor is the combination that points to impaction specifically.

Is pumpkin actually proven to help, or is that just something people say?

It's a widely used, plausible fiber-based aid in exotic pet care generally, not a rigorously tested axolotl-specific treatment — treat it as a reasonable supplement alongside stopping food and seeking vet-prescribed lactulose for anything beyond a mild case, not a substitute for either.

Critical - act now

Swollen belly, floating, and it's had access to gravel

This looks like: intestinal impaction from swallowed substrate — a real emergency, not a wait-and-see symptom

Do this firstStop feeding immediately — more food behind a blockage makes things worse.

Why this happens

Axolotls feed by suction and routinely gulp whatever's under their food. Gravel, small stones, or anything not fine sand or bare glass can lodge in the gut, causing a blockage. Left untreated, impaction can be fatal — toes turning red is another sign sometimes seen alongside it.

How sure are we? Bloating plus known gravel/substrate access is a strong pattern for impaction, but bloating can also mean gas buoyancy or (rarely) ascites — a vet can confirm with an X-ray if home measures don't resolve it quickly.

What to do right now

Stop feeding immediately — more food behind a blockage makes things worse.
If you can get one, a vet-prescribed laxative (lactulose) is the actual medical treatment for impaction and works faster and more reliably than home options.
Pureed pumpkin (a small amount, unseasoned, offered as food) is a genuinely commonly-used fiber aid for impaction in exotic pet care — but it's a supplement to proper treatment, not a replacement for a vet if the axolotl doesn't pass the blockage within a day or two.
Keep water quality pristine during this — a stressed, impacted animal is more vulnerable to secondary infection.
If there's no improvement within 24-48 hours, or the axolotl seems to be in distress, this needs an emergency vet — severe impactions sometimes require surgical removal.

What not to do

Don't keep feeding normally hoping it'll pass on its own with food in the gut — stopping food is the first, not optional, step.
Don't leave gravel or small substrate in the tank going forward — switch to bare bottom or fine sand permanently once this resolves; this is not a one-time accident risk.

Stop it happening again

Bare bottom or fine sand only, permanently - this is the single most important substrate rule in axolotl care, and it's a one-time fix.

If that doesn't fix it

Whatever the outcome, this is the moment to fix the substrate for good — bare glass or fine sand only, checked in our care guide's substrate section, so this doesn't happen again.

Catch this earlier next time — log your axolotl's water parameters in App-aquatic. Free forever.

This isn't veterinary advice - it's a directional read to help you decide your next step, based on the most common causes and independently checked sources (Merck Veterinary Manual, PetMD, established amphibian husbandry references). We can't see your axolotl, so pair it with a liquid test kit and clear photos, and see an exotic or aquatic vet for anything serious or not improving.