Posts: 120. Re: How do I solidify loose stools?! Eat bananas! lots, they will raise your potassium (low potassium can give you a heart attack by the way), but bananas absorb liquid in the bowel and intestined as it travel, reducing watery stool and adding bulk to the stool. bread also can dry up stools. My son is prone to constipation so I rarely give him sandwiches for school. maybe try rye bread even, its pretty dense. otherwise a few spoonfools of cornflour in 1/4 cup of water is an old remedy for diareoh, and is something u can do every day...goodluck.