"The after care has been terrible"

My 75 year old grandad went into hospital to have cancer removed from his bowel. The surgery went well. However he was put on a high dependency ward and the after care has been terrible. There has been several occasions where communication between the staff has been non existent which has resulted in my grandad been starved and missing his insulin as he is a type 2 diabetic. He complained of horrific pain so was sat in a hard chair for 13 hours all night as they thought this would help. It actually turned out his pain relief machine wasn't working and hadn't been for 24 hours. 2 days later he began vomiting and this was every hour. 2 days later it was finally picked up that he was vomiting faeces. It took 2 days for someone to notice.

6 days post op his drains that are draining blood from the wound turn black. Only on the 9th day does someone decide to report it and now he has an infection which could result in another op being needed. My grandad's mental health has become a major concern as he no longer wants to live. No one is addressing this however.

We have had 4 different answers from the same nurse about the same question as she actually doesn't seem to know the answer. I have also been made aware that they are short staffed to the point they can't cope. In my opinion my grandad is going through suffering he shouldn't have to if some staff did their job and took notice.