I have pain in my lower back (anus) when I sit or walk, and especially when I feel like passing gas or having a bowel movemnet, what could be wrong with me. Please treat as urgent, this condition have been going on for the past 5 days. Thanks

I would ask a doctor as it may be a cyst, an obstruction, a colon problem, or some other serious issue if it's really bothering you. Without a lot of information, I can't really tell you what is wrong, but it seems important enough to definitely consult a doctor.