Severe constipation due to multiple sclerosis

Since June 2007 I have been experiencing severe constipation and terrible bloating (I weigh 48kgs and look 9 months pregnant) that is related to my MS ("bowel denervation" is the term my doctor uses).

I have tried the follwoing remedies to try and control the problem (a lot have been taken in combination with each other in vast daily quantities):-
A very high fibre diet and 3L water daily
Coloxyl with senna - 8 a day plus Movicol - 8 sachets a day
Coloxyl
Senokot
Slipery Elm
Bisalax
Motilium
Aloe Vera Juice
Normacol Plus
Normafibre
Lactulose/Actilax
Epsom salts
Inner Health Plus
hi-up enemas
Picoprep
Fibrogel
Benefibre/Agarol/Metamusil
A course of drug therapy with Vancomycin, Metronidazole, Colgout
Maxolon - had to give up due to severe side affect
Rifaxim - had to give up due to severe side affects
Underwent a fortnight of Human Probiotic Infusion Therapy

The only treatment that is working is
6 colgout
3 motilium
18 senokot

However, here in Australia, the Therapeutic Goods Adminstration have reported on Colgouts high toxicity levels and I am extremely worried about taking this medication which I have been on since Sept 2009. (Started on 3 daily but now upto 6).

Is there anyone out there with severe constipation and bloating? Can you suggest any other forms of treatment?

Look forward to hearing from someone!
Jasper