So why the do the painkillers, especially codeine, you’ve been prescribed for chronic pain cause constipation. It is a cruel irony that such effective medication can cause excruciating pain of a different sort. Well, one of the side effects of codeine, indeed any narcotic, is to inhibit peristalsis, which is the squeeze action of the intestine as it propels digested food from the stomach to the rectum. This is why codeine is so effective in stopping diarrhoea. The stools start to dry out as the longer they remain in the intestine the more water is absorbed from them, as the intestine works hard to conserve loss of water from faeces so we don’t dehydrate. This is why our faeces come out solid. The longer they take to come out, the more solid they become. Eventually they can become so hard it is no longer possible to eject them and this is constipation, or in severe cases impaction. If taking codeine regularly it is important to take laxatives now and again along with a good high fibre diet. Laxatives which act by increasing peristalsis will counteract the effect of the opiate. Senna and sodium picosulfate (Dulcolax) will do this but should be used cautiously particularly with prolonged use. Glycerol suppositories act as a rectal stimulant by virtue of the mildly irritant action of glycerol. Some laxatives work by softening the stool – Movicol contains macrogol which is an indigestible sugar which binds to the stools and so draws water back into them by osmosis so is called an osmotic laxative. Movicol also contains sodium bicarbonate, sodium and potassium chlorides (electrolytes) to help ensure that the laxative works without causing the body to gain or lose significant amounts of sodium, potassium or water.
It’s best to experiment with what type of laxative suits you but it is probably better not to take stimulant laxatives daily, as the bowel will become lazy. Senna is the old favourite but many find Dulcolax the best as it gives the feeling you want to go, which one can easily lose when taking opiate-based medications. Start to take laxatives straight away.
Some doctors and pharmacists may downplay constipation as a remotely possible side effect, or one that doesn’t cause too much discomfort when, in fact, it can be excruciating. So take a preventative approach by taking a stool softener and a laxative as soon as you start taking the pain-reliever – it’s easier in the end.
At White Pharmacy we would suggest you try a combination of Movicol and glycerine suppositories (could purchase as a combined constipation pack) in the first instance.
Other really important measures you should take to avoid constipation are to increase your water intake to at least 3 litres each day (it might feel you’re going to pop with all the fluid but it’s a MUST), eat branflakes or similar regularly, lots of fruit especially rhubarb (an intestinal stimulant), oranges, etc. Also fresh vegetables and change to brown rice. If you have pasta, make it wholemeal. Forget pizza and anything that is made from pure refined flour – think cement. To have a healthy diet is really important when you are already ill.
Finally, whilst you may live in so much pain, staying as active as possible is essential. Even it it’s only walking and bending at the waist a few times a day will help get those bowels working properly.
Philip J Toplis has been in NHS and private medical practice as a Consultant Obstetrician and Gynaecologist in Surrey/Hampshire since 1986. He qualified at Bristol University and underwent further training in general surgery and gynaecology at Queen Charlotte’s, Guys and Charing Cross Hospitals, London, the John Radcliffe, Oxford and MD Anderson, Houston, Texas. His sub-speciality expertise includes the investigation and treatment of urinary problems, management of abnormal cervix smears, hormone replacement therapy and menstrual problems. Philip holds Fellowships of the Royal College of Surgeons of and Royal College of Obstetricians and Gynaecologists. He is married with three children and one grandchild. In his spare time he is a charity fundraiser, struggling to become competent at golf and keeping the garden tidy.