Incomplete Bowel Movements-help

I mostly have IBS-C and every day I feel like after a bowel movement there is something left in my rectum. I use a medical grade lubricant on one finger to check. This involves breaking up semi soft to hard pieces and pulling them out. I asked my doctor yesterday about this and he simply said don’t worry if there’s some left inside of me it will come out later. Well, I can’t seem to ignore this.
Im keeping a journal now of exactly what I eat and have added more fruit and vegetables. Im getting over 60 ounces of water a day. Im including exercises, isometrics mostly because I’m disabled and I’m on a low calorie diet.
I was examined some years ago and the doctor said I have a normal sized rectum but a very tight spincture muscle. Im 76 years of age and have been using the lube almost every day of the past 2 years.
Can manual extraction of feces cause a lessened response of my need to go? I have two bowel movements a day usually. Im concerned that I’m doing harm by not just leaving the fences inside but I’ve found that they turn to hard rocks by evening.
I’ve just started using stool softeners and need to know if I can use them often or not?
Your help is appreciated.
JS

I think your last statement was right on. I’m being fixated on having nothing left inside me.
Can I use one stool softener every day?
The instructions are very vague on the bottle.
JS

Miralax is a laxative. Don’t I need a stool softener? I don’t want to become dependent.