I would ease off on the bloodworms, these can cause bloating & constipation. Once in a while is fine, but too much can lead to problems. If you are feeding bloodworms more than once a week, that is too much. Brine shrimp every other day is plenty. I rarely feed mine bloodworms due to the bloating problems they cause, and feed brine shrimp once to 3 times weekly. Try feeding spirulina flake at least once a week, this seems to help keep things regular.
Epsom salt helps with bloating & other intestinal difficulties. Start with 1 teaspoon per 10 gallons of water, increase to 3 teaspoons per 10 gallons over a few days. It's a cheap, readily available treatment that won't harm catfish, and can be used along with other meds.
Tolak