Treating irritable bowel syndrome (IBS) with constipation
Diet and lifestyle changes may be recommended to help reduce the symptoms of irritable bowel syndrome and constipation.
Medication or psychological treatments may also be recommended for this type of IBS.
IBS and diet
Dietary changes can help many people with IBS to manage their symptoms. Fibre reduces constipation by softening the stool, making it easier to pass. Most people in the UK only eat around 14g of fibre a day, some way short of the recommended at least 30g of fibre a day.
Good sources of fibre include wholemeal bread and cereals, fruit, vegetables and beans. Dried plums, prune juice, ground flaxseed and water also help loosen bowels.
Limit coffee, fizzy drinks and alcohol. These can slow the passage of stool, as can refined foods such as crisps, biscuits and white rice.
Remember, different foods affect each person with IBS in different ways. Some people develop diarrhoea and wind when they eat too much fibre, or certain high-fibre foods, so it’s a good idea to keep an IBS symptom diary to determine which foods your digestive system can handle. Just write down your IBS symptoms, then note the type and amount of food you ate during the meals before your symptoms appeared.
Fibre supplements for IBS
Some people use bulking agents, commonly known as fibre supplements, to treat IBS with constipation. These include:
- Wheat bran
- Psyllium (ispaghula husk and others)
These supplements may increase bowel movement but they do not appear to help with other IBS symptoms, such as stomachaches, discomfort and swelling. In fact, extra doses of fibre may worsen abdominal pain, bloating and discomfort in some people with IBS.
Laxatives for IBS
These types of medications are for short-term use.
Many people with IBS take laxatives but these may offer limited relief and can cause problems if taken regularly for weeks at a time.
Laxatives work well for occasional constipation, but they don’t usually help relieve other IBS symptoms, such as stomachaches and bloating. Also, some laxatives may be habit-forming and detrimental if used over a long period of time.
In stimulant laxatives, the ingredient senna triggers muscles in the bowels to contract, moving stool through the bowel. Over time, the chemical can damage nerves in the colon wall. Eventually, these laxatives may stop working. Stimulant laxatives include senna, bisacodyl and docusate sodium.
Other laxatives, called osmotic laxatives, pull water back into the colon to soften stool, which makes the stool easier to pass. But research has found that they don’t relieve IBS symptoms other than constipation. In fact, they may actually worsen other symptoms. Side effects include diarrhoea, dehydration and bloating.
Antidepressants for IBS
Your doctor may prescribe a low dose of antidepressants for IBS. This does not necessarily mean that you are depressed. Antidepressants can block the brain’s perception of pain in the gut.
There are different kinds of antidepressants and the one your doctor chooses for you may depend on whether you suffer from constipation-predominant IBS or diarrhoea-predominant IBS.
SSRI (selective serotonin reuptake inhibitor) antidepressants do not usually cause constipation. Their side effects include nausea, loss of appetite and diarrhoea.
Other older antidepressants (called tricyclic antidepressants) tend to cause constipation. Doctors usually prescribe them for IBS patients with diarrhoea. Other side effects of tricyclic antidepressants include dry mouth, drowsiness and blurred vision.