The diagnosis of moderate congestive heart failure (CHF) means that the pumping mechanism of your grandmother's heart is moderately impaired. In general, this level of heart "failure" will respond to
certain cardiac medicines which can help in a variety of ways: assist pumping action, dilate blood vessels, or help eliminate extra fluids in the bloodstream. I don't know what caused the bowel obstruction your grandmother had, but it sounds as though your grandmother is dealing with several medical issues. With this new diagnosis of moderate CHF, medications will be prescribed and she is likely to be fatigued. In a best-case scenario, she will recover from the cause of obstruction, from the surgery itself, and her cardiac function will respond well to medication. If all the above occurs, she should be able to resume at least some of her former activities. I wish her a speedy recovery.