Things have definitely improved in the last few years, mainly due to the influx of students. Best place that stays open lateish is probably The Mustard Lounge which is next to the Golden Lion inthe town centre. I think that's open til about 1:30 on Fri/Sat. Alpine (near the indoor market) also opens late but has a reputation for having a lot of underage people in there. The Forum (down Railway Road) is a newish place and has a good outside bit if your lad is a smoker. To be honest though, if he's up for a 2/3am'er, his best bet is going down to Liverpool.
What I think Ormskirk has got better at recently is having a few tidy places to have a casual drink. The Hop Inn Bier Shoppe is excellent down on Burscough Rd and Lime Tyger on Church St is pretty decent. The Green Room (below the Mustard Lounge) is nice and often has live music on. You've got a decent selection of pubs with the Buck ith Vine being the most student friendly. A good place for a cheap pint before a night out is the Queen Inn on Aughton St - used to be £2.50 for a double vodka coke.
Anyway, hope your lad has a cracking time at uni. Was up on the Edge Hill site a couple of days ago and it looks class.