Yes, it's entirely normal. These are all well known side effects of opiates. The constipation is due to the fact that the gut contains opiate receptors which when activated, decreases gut motility by inhibiting peristalsis. This is why loperamide (a weak opiate) is used as a remedy for diarrhea. The inability to shoot your load can be explained by the general desensitising effect of opiates. It's great at first because you can shag like a porn stud on Viagra - but can get a little frustrating, especially when the bird you're shagging is also on gear and can't get off either. I don't know why it makes it difficult to piss tbh, but I've lost count of the number of times I've stood over the toilet for ages, repeatedly gouching out and doing woodpecker impressions on the bathroom wall...
