If your betta fish suddenly swells, he may be constipated. You need to treat this problem soon. The first way to help constipation is to stop his regular diet for a few days. That will give him time to digest and move food through his system. After a couple of days, start feeding him again. However, you should stick to live food for a little while. For live food, you can feed brine shrimp or blood worms. The general rule on how much food to provide is give enough food so that your betta can eat for two minutes. Do so twice a day. Constipation is generally a sign you are feeding your betta too much. Therefore, once he starts eating normally again, you need to feed him less than you were.

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Write a summary of the previous text in Vietnamese:
Kiểm tra các dấu hiệu sưng phồng. Ngừng cho cá ăn thức ăn bình thường trong nhiều ngày. Cho cá ăn thức ăn sống. Không cho cá ăn quá nhiều.