About 6 weeks ago, my Betta fish, Clarence, stopped eating.
Also, he stopped doing his one trick, which was - when I pressed my finger against the outside of his bowl, he would flare his gills and swim over to where my finger was. Then I would hold my finger just above the water, and he would jump up and nudge it. After which I would feed him.
After some Googling, I came across the notion that maybe he stopped eating because he was cold - I keep my house 8 degrees cooler in winter than in the summer, when I got him.
So I put a standard electric heating pad under his little 1 gallon bowl.
Soon he was building bubble nests - which is always a good sign of a happy fish - but not eating.
But after about a week, he *did* start eating again.
And he's doing his one trick again, too.
So, yeah, what the internet says about Betta fish being able to go without food for a month is true. So if this happens to you, keep him warm, keep offering food, and just wait it out.
A little prayer couldn't hurt, either...