To Dennise.T.
Had a couple of thoughts about your father. Firstly, the dueodenum is the second stage of digestion and absorbtion. Losing it and part of the pancreas or all of it means the system is no longer working any where near normal. The small intestine is learning how to work with out the missing parts. Enzymes produced by the pancreas may be non existant or not enough produced. Enzymes help break down food for absorbtion, so they may not absorb medication very well untill enzimes are there insufficient amount. May mean creatine supplements. Its very early days yet, consult surgeon. Give as much support and love as possible. I hope this might help.