coding and modifier help please?

We have a patient with severe necrotizing pancreatitis, which is compromising the integrity of his other organs. So far during his prolonged hospitalization he has had approximately 80% of his pancreas debrided; he has had erosion of veins & arteries requiring emergent repair, and he has had bowel necrosis and erosion at the splenic flexure.

He had a Hartmann's for this, with a right-sided colostomy & closure of the distal end at the splenic flexure.

The necrosis of the colon continued to spread, so he had a colostomy revision.

The necrosis is still spreading, so now the surgeon has removed the entire right colon and part of the terminal ileum (up to viable tissue) and created an end ileostomy. He also found that the distal end of the previous Hartmann's has eroded, so that was revised and reclosed. This is the surgery I'm trying to code now.

(Although he doesn't call it that, the doctor makes it sound like abdominal compartment syndrome.)

All these surgeries have been done as the direct result of the patient's worsening original condition, NOT as a result of complications of previous surgeries, right?

I think I'm leaning towards 44143-58, but I'm not too confident about it.