Im concerned about stool shape/caliber. the first half is normal (round like a banana, normal diameter, slightly bumpy) but the 2nd half is like a squashed sausage (between flat and round). normal color. no pain. stool is very soft. is this normal?

Stool calibre: I don't see anything serious here. You may have a type of irritable bowel syndrome where intestinal activity varies from sluggish (forming firmer,lumpy stool) to more active intestinal peristalsis causing looser,flatter stools on a day to day basis. Are you aware of any foods that trigger loose stools? If you still have concerns, consult a gastroenterologist for evaluation and advice.