Is this normal

Hi all,  my dad has throat cancer and treatment has not worked and we have been told its spread to other parts of his body. We know he has only a certain amount of time left. He struggles to swallow due to the cancer and he drinks shake supplements and manages soft food in small amounts. We have continuing health care where carers go in four times a day to given him his medication. What I need help to get my head around is his behaviour and the sudden lying. For example, he will tell a family member that he has bad stomach pains and can not go to toilet, so im informed of this and contact the local goldline who sends out a nurse to see him. So the nurses goes at nighttime to him saying there's nothing wrong with him. I get a call the following day to tell me what he said. So I go over to try and sort out the issue and he says he's bunged up and has pains. He's asking for laxatives because he is putting his fingers up his bum to help move the blockage. So I arrange for medication which is prescribed and since the 1st September he is allowed laxatives 4 times a day and reading the notes he's refused every dose, but tells me he not been given to him. He gets agitated when confronted. Is this normal for them to lie. One minute he can't eat anything then next he's wanting fish and chips. I can't tell if these are actual things people do when their dying or is he playing us off against one another. I don't want to thing the latter but its strange.