I am getting an impression that you still have lower bowel problems.

Cramping there, causes nausea. I have a complex severe GI congenital defect.
Let me share this with you. The feelings preceding an obstruction are silent, until ischemia starts to develop and then pain starts. There is really little
feeling in the intestines, otherwise. But you can feel cramping and distention from gas.

Feelings of "going to explode" suggest to me, GAS. And since you do not
consume fiber, which would help absorb gas produced by bacteria in the bowel,
your colon is not functioning properly.

The majority of whey products are lactose free. This is because the manufacturing process does not pick up the lactose portion.
example: http://www.qfac.com/whey_protein.html
Lactase enzyme is available in drops to add to any food/drink dairy based. And there is a Lactaid milk, which is very good (I use it).

I am starting to think that you may need l-glutamine supplementation. This amino acid is necessary for the normal maintenance of the lining of the GI tract. Please read this:
http://findarticles.com/p/articles/m...20/ai_20801957
The author is James LaValle...who co-wrote Drug Induced Nutrient Depletions textbook.
and this: http://en.wikipedia.org/wiki/Glutamine

I think you have multiple problems, and this makes your task much harder to
accomplish. Gastroparesis nerve damage, and nasty bacteria in the bowel!

Some whey protein products have extra l-glutamine added.
this is an example:
http://www.nowfoods.com/?action=itemdetail&item_id=3105

I am also worried that you are not getting enough potassium. This is a critical electrolyte.

Commercial bouillon contains hydrogenated fats, high sodium, and monosodium glutamate..which is an inorganic form of glutamate hard to tolerate.

And you need to consider that anything going into a J-tube will end up in the problematic colon anyway.

Have you tried simethicone? This helps one pass gas. It is available in a liquid form-- drops (intended for babies) but it can be used by adults. It may help with the gas/distention discomfort.

I don't know what else to suggest.