Abdominal pain after VP shunt. Anything.

My father had a haemorrhagic stroke in right side 4months back following which he had craniectomy and 1 month after had his cranioplasty, 20 days after that he developed hydrocephalus and had to undergo VP shunt. It's been 20 days since and now he complained about right side abdominal tenderness, constipation, feeling full all the time, 2 days after he developed a fever, his CBC showed borderline infection, not much and his NS said nothing to do with shunting, but we are still concerned, we are noticing a difference in his mood and behavior and his walk as well. His fever is gone now and his constipation has improved a bit, but all the other signs persists and he is not feeling good, always sleepy and weak and unmotivated to do anything.