Betta Fish Constipation: The Complete Guidebook to a Bloated Betta Fish

Bettas are amongst some of the easiest species of fish to keep. They are not only hardy, they are also not picky and voracious eaters. To add, they come in a myriad of colors, making them an extremely popular choice for beginners wanting to keep fish for the first time.

Constipation can occur for many reasons, i.e lack of movement due to small space, however, the most common reason, is due to overfeeding.

In this article today, we take you through the reasons why constipation happens, the dangers, diagnosis, treatments, and prevention measures. So be sure to read to the end of the article!


Constipation happens for a number of reasons, and it is so important to scrutinize your husbandry methods to accurately identify what the most probable cause is.

DIET This is generally the most common reason why bettas get constipation. In the wild, bettas are carnivores and feed on live food from worms to insects that fall to the surface of the water.

Their diet in the wild has loads of chitin (a fiber that is found in the exoskeletons of insects), which facilitates their bowel movements.

In the home aquarium and in part, due to their “I’ll eat anything, just feed me” attitude, most owners feed them an exclusively dry pellet based diet.

While this in itself is not bad, it does cause problems for their dietary track as it lacks the finer requirements for the fish.

Overfeeding Most new owners tend to overfeed their bettas because it is a common mentality to “feed until my fish is full”.

I can understand this and I have totally been there myself, the allure and the joy of feeding your new pet fish is a joy few will understand!

However that said, bettas are opportunistic feeders in the wild and will continue to eat when given the chance. Therefore in the aquarium when presented with food, many hobbyists latest that the betta will most likely eat themselves to death.

Yes, it is as bad as it sounds. Overfeeding can cause blockages in their digestive tract as digestion can’t keep up with the amount of food the fish is consuming. This, in turn, causes a buildup of bacteria in the fish resulting in bloating due to the gasses released by the bacteria and if left untreated, could lead to death.

Lack of Exercise If you’ve taken some time to observe your betta, you’d realize that it is a rather sedentary fish. Betta fish can sometimes be really lazy and remain in the same spot all day without so much as the flutter of a fin.

In the wild, however, bettas are more active because they need to hunt for their food and defend their territories.

This lack of exercise while not a direct cause of constipation, does affect the chances of the betta getting constipation greatly.

Exercise is important because it keeps the fishes digestive tract working and reduces the chances of a blockage happening.


While constipation in itself is not extremely dangerous, it will lead to very serious issues very quickly if left untreated. Therefore it is good to equip yourself with the knowledge of constipation symptoms. Spotting constipation in bettas is not exactly difficult if you know what to look out for. Some telltale signs include a bloated tummy, stringy poop, not eating, lethargic.

While there are some other indicators, these 4 are possibly the most obvious.

Bloated Tummy This generally happens after a big feeding. If you see this happen, you might be feeding your fish a little too much and you should probably tone down on the feeding.

While in itself is nothing much, a bloated tummy for a prolonged period of time ie 3-4 days could spell a blockage in your betta.

You should also note that females generally will have larger bellies when they are sexually mature due to the eggs they might be carrying.

Stringy Poop Stringy poop is also a cause for concern because healthy betta poop comes in little blobs. That said, hanging poop is a problem because it signifies the digestive system in overdrive trying to process all that food in the betta.

It is also probably important to mention that healthy betta poop is dark brown. White stringy poop could also signify a bacteria infection or internal parasites.

Anorexia Bettas are by nature, voracious eaters, such that it is a skill to know when to stop feeding your betta because they just keep eating.

So when your betta stops eating, for whatever reason, its a problem.

Lethargy Bettas are generally not very active fish by nature so this symptom might be bit difficult to spot. However that said, bettas will become active when certain conditions are met, i.e feeding, another male is presented, female is presented.

If you see that your fish is not reacting to these stimuli, you should automatically assume something is wrong and observe the fish more closely.

These symptoms can occur alone or in a combination, it is best to take a look and observe your fish and its habits as an individual before making a judgement call on whether it has constipation.

However to err on the side of caution, you can assume that they have constipation if any one of these symptoms are showing.


Thankfully, treating constipation is not difficult. Here are some effective methods of treating constipation without doing any harm to the fish!


The fastest way to clear constipation is to let your fish fast. Generally, 2-4 days should suffice, and your fish should be back to normal, however, if you see that your fish is continually bloated or lethargic after the 4th day, continue to let it fast (I’d recommend no more than 7 days) until it passes the blockage.

While this is a good option, sometimes fasting in itself is not enough and some other methods might need to be employed. However, in my experience, fasting works 90% of the time!

Dietary Changes

Most of the time, constipation happens because of commercially prepared dried foods that expand in the fish’s gut causing a blockage. Do you think it would be a good idea to continue feeding dried pellets? I don’t think so!

During the constipated period, many keepers, myself included have found that a peeled boiled pea will help with clearing the blockage and introduce a good source of fiber into the betta.

Peeled boiled peas should be tried only after the fish has fasted for a few days so that the digestive tract has had some time to work. You can try 1 pea every 24 hours.

Raise the water temperature

Ensure that the water in the aquarium is warm enough for betta fish. The suitable temperature for betta fish should be between 21 and 26 degrees Celcius. If the aquarium is not heated to that level, your fish may enter a low-metabolic rate, which slows down the digestive process. In order to avoid this issue, you should equip your betta tank with a heater. This will ensure that the water temperature is comfortable for your fish and reduce the risk of constipation.

Move it to a bigger tank

Sometimes all the betta needs is a little bit of exercise. Changing up the environment could not only clear the blockage, but it could also increase your betta’s overall health!

Medication If all else fails, try medication. While medication is generally used as a last resort, it is important to note that even with medication, some fish will die.

That being said, a common practice in the hobby is to use Epsom salts (magnesium sulfate), which is actually not salt (sodium chloride). Epsom salts act as a laxative as they help in relaxing the fish which also reduces stress.

Most keepers recommend an Epsom bath, where the fish is placed in a separate container containing 3 to 4 teaspoons of Epsom salts dissolved in 5 gallons tank water for about 30 minutes twice to 3 times a day.


Constipation is a disease is very preventable. As long as you follow a few simple rules, I’m certain even the most novice of fish keepers will do well.

Varied Diet This is probably the most important aspect of preventing constipation.

Remember that to have a balanced diet, bettas should be fed a mixture of meaty foods on top of their staple dried pellets, which include tubifex worms, mosquito larvae, bloodworms etc.

To add, you can also pre-soak the commercial pellets before feeding them to your betta to prevent it from expanding in your fish too quickly, which might cause blockages.

Don’t Overfeed Overfeeding causes other issues down the line which will ultimately reduce the lifespan of your betta.

The betta’s stomach is roughly the size of its eyes, which is pretty small, to say the least. A good gauge as to how much you should feed is to feed it for about 2-3 minutes every day.

As bettas will continue eating its easy to see why owners will worry when they stop feeding thinking their bettas are still hungry. But do not worry, bettas need little to survive, and feeding 2-3 minutes a day is plenty!

Tank Size
Increasing the size of the tank can also help with reducing the chances of constipation happening as more space equals more chance for movement to happen which will result in better bowel movement and a more active fish!


Constipation in bettas is a common but easily treated and very preventable disease in bettas. If you spot any of the symptoms like what we’ve mentioned above, be quick to act so that your betta has the highest chance of survival. Remember, constipation if left alone will quickly develop into other more serious complications.

That being said, preventing constipation is incredibly easy!

  • Varied Diet
  • Dont overfeed
  • Increase your tank size

As long as you follow these simple rules, your betta will stay happy and healthy!

Till next time, thanks for reading!

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