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What can cause a change in bowel habits?

Medically reviewed by Neka Miller, PhD on June 15, 2020. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.


A change in bowel habits (such as changes in frequency or stool consistency) can happen for all sorts of reasons. You might feel constipated after a day of traveling, for example, or experience diarrhea when you’re especially stressed. Gastrointestinal disorders like celiac disease and ulcerative colitis can also affect bowel habits—as can serious conditions like colon cancer.


Related: Who is at risk for colon cancer?


So what could be the reason for a change in bowel habits you may be experiencing? Here we’ll cover some common causes—including lifestyle factors and health conditions—so read on.

Common causes of a change in bowel habits

Travel

Traveling and changes to your schedule can cause altered bowel habits, especially if you’re not getting adequate water (which can be especially common on long drives or flights).

Exercise

Physical activity can affect bowel habits, and if you’re experiencing constipation it may be because you aren’t exercising as frequently as you used to.

Dairy

When consumed in large amounts, dairy products can lead to a change in bowel habits.

Stress and anxiety

Stress and anxiety can disrupt many processes in the body—and that includes the gastrointestinal system. So whether you’re experiencing constipation or diarrhea, it could have something to do with stress or anxiety.

Laxative use

Overusing laxatives can weaken bowel muscles over time and trigger a change in bowel habits.

Medication side effects

Certain medications like antidepressants, iron supplements, and opioids can also affect your bowel—as well as antacid medicines that contain aluminum or calcium.

Resisting the urge

Resisting the urge to have a bowel movement can lead to constipation later on.

Pregnancy

It’s normal to experience a change in bowel habits when you’re pregnant. Constipation is relatively common during pregnancy and may be due to shifts in hormone levels and lowered fluid intake and fiber consumption.

Gastrointestinal disorders

In addition to the factors discussed above, gastrointestinal disorders can also lead to a change in bowel habits.

Ulcerative colitis

Ulcerative colitis is an inflammatory bowel disease. It causes prolonged inflammation and sores, or ulcers, in your digestive tract. Symptoms vary but can include a change in bowel habits like diarrhea (often with blood or pus), increased urgency, and constipation.

Crohn's disease

Crohn's disease is another inflammatory bowel disease that causes inflammation in the digestive tract and can lead to severe diarrhea.

Celiac disease

Celiac disease is an immune system reaction to eating gluten, a protein commonly found in wheat, barley, and rye. This immune response may cause a change in bowel habits (like experiencing diarrhea or constipation).

Irritable bowel syndrome

Irritable bowel syndrome, or IBS, can cause the small and large intestine (the colon) to contract more often. This can lead to bloating, excess gas, abdominal pain and cramps, diarrhea, and harder, looser, or more urgent stools.

Bowel habits and colon cancer

A change in bowel habits may also be connected to colon cancer, particularly among people age 50+ (who face the highest risk of colon cancer). The type of bowel habit change can differ from person to person (and colon cancer doesn’t always affect bowel habits), but more frequent bowel movements or looser stools—or both—are especially common. More rarely, narrow, “pencil-thin” stool can also occur.


Related: Early signs of bowel cancer | Signs of colon cancer in women


If you’re concerned about the symptoms you’re experiencing, talk with your healthcare provider right away. Additionally, routine screening for colon cancer (once a year) is recommended if you are age 50+.

Fortunately, you can conveniently screen for colon cancer from the comfort of home with the Everlywell FIT Colon Cancer Screening Test. Sample collection is simple and results are easy to share with your healthcare provider—so consider this home option if you’re due for an annual screening.


References

1. Gastrointestinal Disorders. Cleveland Clinic. URL. Accessed June 15, 2020.

2. Opioid Induced Constipation. StatPearls. URL. Accessed June 15, 2020.

3. Vazquez JC. Constipation, haemorrhoids, and heartburn in pregnancy. BMJ Clin Evid. 2010;2010:1411.

4. Trottier M, Erebara A, Bozzo P. Treating constipation during pregnancy. Can Fam Physician. 2012;58(8):836-838.

5. Ulcerative Colitis. MedlinePlus. URL. Accessed June 15, 2020.

6. Crohn disease. MedlinePlus. URL. Accessed June 15, 2020.

7. Celiac Disease. MedlinePlus. URL. Accessed June 15, 2020.

8. Spastic colon: What does it mean? Mayo Clinic. URL. Accessed June 15, 2020.

9. Irritable Bowel Syndrome. MedlinePlus. URL. Accessed June 15, 2020.

10. Hobbs FD. ABC of colorectal cancer: the role of primary care. BMJ. 2000;321(7268):1068-1070. doi:10.1136/bmj.321.7268.1068

11. Narrow stools: Should I be concerned? Mayo Clinic. URL. Accessed June 15, 2020.