Like u said I think he has swimbladder problem but it also can be other infection.
Here is what might cause the problem (you can read it from our faq page):
Internal Bacteria
Symptoms
a. In some cases fish will darken in colour, become listless, stop feeding and die.
b. In other cases, severe symptons exist, ulcers, abdominal (dropsy) and eye swelling (pop eye), destruction of the central nervous system and then the fish dies.
Influencing Factors - Poor water quality will stress the fish and make them susceptible to infection. Also fin and body tissue damage will give the bacteria a site to start infecting.
My Experience -I recently lost one of my Mollies she was black so i did not notice her darken in colour, but she hid all the time and stopped eating, then died. At the point she died four other mollies and two platies started to hide and not eat. Also around this time started to notice that some of the fish had long stringy white feces (poo), it was 5 inches long in some cases.
I did a 30% water change and added Interpet No 9 for internal bacteria, plus two spoons of salt. Next day I added two more spoons of salt. On day four I put in the second dose required of Interpet No 9. Then nothing else and no water changes for the next 8 days. On the day four (after second dose) one of the mollies passed a lot of white gooey stuff and after that he started to come out at feeding time and occasionally take one or two nibbles.
All fish were fine at the end of the 8 days, out from hiding and eating again. Some did however still have a bit of stringy poo. I was therefore advised to do a 25% water change and clean up and redose the medication without salt. This is mainly as a precaution because the disease can come back if it is not "completely" cleared up.
Reason it happened - I did not know at the time buy my pump housing was blocked my pump hardly running at all. My water parameters did not show there was a problem but the pump must have been getting slower and slower over a period of time and therefore the oxygen was getting lower and lower. I believe this is what caused the bad water conditions that kicked in the infection for my fish.
What I have learnt - Fish commonly get ill because of poor water quality. I knew I had not introduced anything new, I did regular water changes and my tests were all good. How could it be poor water quality. It was because of the pump problem. I say don't give up looking there is always a reason, don't just treat the disease, find out why and learn from it.
Here is the possible way to cure swim bladder disease but due to the disease isn't really cause by bacteria or parasite its very hard to treat because its the fish's internal organ problem.
Swim Bladder Disease
*Problem occured with Male Betta... same betta as above*
Treat with Melafix every fortnight and salt everyday and a water change every fortnight... not the same day as putting in the Melafix. Feed Hikari Betta Pellets.
*Conclusion: When I changed to Hikari Betta Pellets the male betta become much more active and always looked forward to every meal. When adding the salt betta looked much healthier and swam around more. Melafix helped repair the tears in his fins that had been created by the exesive tail movement and the more water changes done the better*
All these treatment were done by me and most of them worked just fine. The treatment also worked with that fish that had the problem so please don't blame me if you try the same treatment to a different fish and it dosn't work.
A nice site you can take a look at with alot of pic and information
http
/www.fishpalace.org/Disease.html#External
Any tread from this site about swim bladder
http
/www.fishforums.net/index.php?showtopic=115493
I have this problem before as well on one of my angel from 25g but it past away before I was able to treat him but curing this disease is very difficult there are all kind of medicine that claim to cure this problem but does it really do the job I dont know. You can go to ur LFS ask them for medicine usually they should have some stock.
Good luck
Jack