Constipation is a common problem. Most people experience some difficulties with bowel habits from time to time; however, constipation may be an ongoing problem for some. This summary is intended to help patients understand the medical approach to constipation and highlight some lifestyle changes which will help overcome some of the discomfort associated with this problem.
In order to address constipation it is important to clarify some terms.
“Constipation” means different things to different people. For the sake of communication we will describe constipation as infrequent bowel movements with hard stool. A consensus conference (Rome III) used the following with more than 2 being sufficient to attach the term constipation.
- Straining with more than 25% of bowel movements
- Lumpy or hard stool more than 25% of bowel movements
- Sensation of incomplete emptying more than 25 % of the time
- Sensation of “blockage” or obstruction more than 25% of BM
- Fewer than 3 BM per week
- Manual removal of stool more than 25% of the time
- What is normal for bowel frequency? The first concept is that it is not necessary for the bowel to empty daily. Normal variation in bowel frequency is wide and it may be normal for some persons to have 2 bowel movements per week as long as they are not uncomfortable or having to strain or use laxatives. Some people may normally use the bathroom 3-4 times per day.
- What is a “good bowel movement”? This concept has much more to do with expectations and the sense of complete emptying. There are many reasons for a person to have the sensation of inadequate emptying and most do not have anything to do with a disease process. Remember that the sensation of inadequate emptying may have nothing to do with the quantity of stool in the colon.
- The colon is a fantastically complex organ that processes indigestible waste material left over from the food we eat. The colon exchanges sodium, water, and fatty acids. The colon contains a complex variety of normal bacteria that interact with the immune system. Stool is a normal component of the functioning colon. The amount of stool in a colon will vary widely among individuals. The entire colon does not empty with a bowel movement. I do not immediately become concerned when an x ray of the colon shows “a large amount of stool”. This quantification will vary among individuals reading X-rays and the reading should be integrated into a clinical picture. For example, I am often consulted to see a person with abdominal pain that has an x-ray read as a stool impaction or a colon containing a large amount of stool. This person’s pain is often assumed to result from “constipation” even if the patient is having daily bowel movements. The course of laxatives that followed did not help. The value of physical examination, careful history, and integration of labs or x-ray cannot be overemphasized.
- The history of bowel habits preceding the current problem is very important. Dramatic changes in bowel habits may signal a serious problem and should be investigated. Colon cancer may present with changes in bowel habits interpreted as constipation.
- Medications are a very important part of the history. Several classes of medications commonly lead to a change in bowel habits. Did you know that Imodium and Lomotil are narcotics? These medications slow many gut functions including colon motility. You should expect that the narcotics provided for pain problems will have a similar effect on bowel frequency. Many classes of medications are commonly associated with constipation such as:
- Anticholinergics such as bladder control medications
- Vitamins containing iron
- Some blood pressure medications like cardiazem
- Aluminum based antacids
- The process of emptying the rectum is complex. Muscles within the pelvis position the rectum to allow stool to pass. Lack of relaxation of the sphincter muscles will stop the process. The rectum changes shape during the process of emptying. The rectum is normally shaped like an “L” and if the angle narrows nothing will come out. Straining may actually prevent emptying much like a kinked hose will not allow passage of water. Pelvic surgeries and previous injuries during childbirth may have a significant effect on the nerves that coordinate the normal sensation and muscular function of the rectum. Similarly spine and back problems can greatly affect colon function and normal emptying.
- Several disease processes commonly affect the colon and rectal function:
- Multiple sclerosis
- Parkinson’s disease
- Any disease that leads to immobility
- Thyroid disorders
- Muscle disorders
- Many others
Colon cancer may present with changes in bowel habits interpreted as simple constipation.
Once a thorough evaluation has been completed and the above factors considered there are several options available to ease the problem. I typically favor an option that is inexpensive, safe over time, and can be sustained. Although the benefits of fiber additives are debated in the medical literature it seems that this safe and inexpensive option is the place to start once medications and disease processes have been considered and addressed.
There are many available fiber options available over the counter. Some people will not tolerate fiber but most simply don’t take enough. Do not expect fiber to keep working when you don’t continue its use. Twelve grams of fiber is usually enough to bring about a change in bowel consistency and frequency. For reference common breakfast cereals contain widely varying amounts of indigestible fiber.
- Honey Nut Cheerios: 3 grams per cup
- Shredded Wheat: 6 grams per cup
- Special K: 1 gram per cup
- Raisin Bran: 12 grams per cup
- All Bran: 24 grams per cup
Fiber supplements like Fiber Sure, Metamucil, Citrucel, Kon-syl can be a good source of additional fiber.
When fiber is not helping there are several alternatives that your physician may suggest. Remember that your other medical problems like renal failure may limit the use of magnesium products like Milk of magnesia. Glycolax and Miralax increase the amount of water retained within the colon. Softer stool is the usual result. The only difference between hard and soft stool is the amount of water held in the indigestible solid waste. Although drinking water may be desirable for other reasons this does not necessarily result in increased water at the end of the colon.
Periodic use of stimulant laxatives may be a reasonable option. Many find that the laxative effect decreases with time. Cramps and unpredictable sudden bowel movements can be a problem. I rarely use stimulant laxatives like Ex-lax and Dulcolax in the management of chronic constipation. Note that herbal laxatives are touted as being natural but contain the same active ingredients as the “ unnatural” laxatives. Look for a class of compounds called anthranoids. The following are examples: cascara, senna, phenolphthalene, castor oil, bisacodyl, aloe, sennosides, frangula, and rheum.
Enemas and suppositories
These may at times be helpful. Talk with your doctor first before using these regularly. Water is this author’s preference if enemas are needed. Avoid soap and other irritants.
Newer medications like Lubriprostone (Amitiza) have unique actions within the colon that increase stool frequency and improve stool consistency. Drug pricing is probably the major limiting factor.
The use of colon cleansers is strongly discouraged. There is nothing natural about “cleansing” the colon.
Remember that this information is no substitute for a clinical evaluation by your physician. For the sake of understanding the processes and actions described above have been simplified. Cereal names and drug names are registered trademarks.