<s>[INST] My brother is married person and got problem with night fall regularly.bcoz of this he feels very week.he is almost sure that because of regular night fall he got liver problem too.He told me that few years back,once he had sex for 90 mins while he was drunk and he fainted and woke up in the morning,after that he is having problem with lower stomach(just above the penis) and from that time he is having nightfall problem. [/INST] Hello Its completely normal to have nightfall in teenage and adults, however it could be due to excessive masturbation,over production of semen or its thin consistency, weakness of semen holding tubes, excessive use of semen producing diets, avoiding sexual act for a longer duration of time and weakness of kidneys as well. I suggest you to visit your doctor  for your brothers detailed checkup and proper treatment if needed I hope i have answered your query. </s>