It’s sometimes not an easy distinction between a hemorrhoid and a fissure, even for some professionals. Pain with defecation, plus or minus bleeding, may be present with both. Also, some extra skin in the region is another common occurrence. Now, with fissures, many describe the defecating as “shitting razors” and you feel a significant anal muscle spasm along with this sensation. This can last for a considerable amount of time after each bowel movement and even debilitate you enough that you have to lie down.
As for external hemorrhoids, it’s pressure and you can feel a clot from the size of pea all the way up to a walnut protruding externally. Most hemorrhoids, geographically, are noted on either the left or the right side, whereas a fissure is more posterior towards the tailbone.