Internal Parasites/Constipated Help

[AhHengBetta]

I suspect one of my betta is suffering from Internal Parasites (or maybe Constipated), The Stomach look full (Just nice type). Been 1 days since he never eat (plan to let it go foodless for 3 days), Scale everything is ok, But the poop is white colour (got poop 1 time).

He is blowing bubble but keep hanging up near the surface of the water. Can someone recommend what the best treatment for it?

Been keeping him in age water with espom salt in his tank, for almost 2 days. no poop yet. Trying to feed pea, but not eating.

Any idea usaully it take how long to cure?

[ChoclateBetta]

What is the tank stats?

[Lizzie the Badger]

Answer these-Housing
What size is your tank?
What temperature is your tank?
Does your tank have a filter?
Does your tank have an air stone or other type of aeration?
Is your tank heated?
What tank mates does your betta fish live with?

Food
What type of food do you feed your betta fish?
How often do you feed your betta fish?

Maintenance
How often do you perform a water change?
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change?

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed?
How has your betta fish's behavior changed?
When did you start noticing the symptoms?
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?

[AhHengBetta]

Answer these-Housing
What size is your tank? 3 gallon
What temperature is your tank? 29
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? no
Is your tank heated? No
What tank mates does your betta fish live with? No

Food
What type of food do you feed your betta fish? recently just use hikari bio pure blood worm (suspect that the cause)
How often do you feed your betta fish? 2 time per day

Maintenance
How often do you perform a water change? 1 week
What percentage of the water do you change when you perform a water change? 100%
What type of additives do you add to the water when you perform a water change? IAL

Water Parameters:
Have you tested your water? If so, what are the following parameters? No

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? Suspect Constipation. been almost 3 days no poop, on 27 sep did see some small white poop.
How has your betta fish's behavior changed? rarely swim, hang on surface of water
When did you start noticing the symptoms? 27 sep
Have you started treating your fish? If so, how? Espom salt + yellow powder in tank. and also tried espom salt only in tank.
Does your fish have any history of being ill? no
How old is your fish (approximately)? 3.5