I was diagnosed with a external hemmoroid and anal fissure a couple of months ago. The discomfort has gotten much better although sometimes when I have a BM I feel a slight pain when I am starting to push the BM outt. It is only in one spot. Is this common?

Probably fissure is not healed completely. Make sure you don't push BM, this will help with hemorrhoid and fissure re-occurrence.

Hi,
Igrik is spot on!
Please don't push! and yes, the pain you are feeling is likely to be coming from the fissure area warning you how delicate the area still is after tearing.
You sound like you had an acute fissure (one that was easier & quicker to heal) and trust me, the last thing you want to do is any further damage and make it turn chronic, one that can take people YEARS to heal from, with a lot of pain & discomfort at stages in between.
Make sure your BMs are always soft & solid and fall out with minimal, even better, no, straining at all - there are hundreds of tips on this website if you need them....
Anyone on this site reading your post would urge you 100% to always ensure you look after your bum the best you can because an unhealthy bum can be really painful and stressful to live with. All the very best to you :)

Thanks so much to both of you for the information.