Other factors Gravity When you are able to sit for four hours or more in your wheelchair, we will encourage you to getup to the toilet using a shower chair or commode. Gravity helps move the stool down into the rectum. We will offer you a variety of chairs to try. Check your skin regularly as some shower chairs or commodes can be a bit hard. If you cannot use a shower chair e.g. you have a pressure sore, lie on the side that leaves your dominant hand free. Exercise Physical exercise stimulates bowel function the more active you are the easier it is for the food to pass through the digestive system. You may find you become constipated during bed rest and you may have to change your bowel medication during this period. Smoking There is some evidence that smoking directly affects colonic function. It is thought that nicotine can stimulate peristalsis (involuntary muscle movement) in some occasional smokers and decrease it in some habitual smokers. For these reasons (and many others, you may want to consider stopping smoking.