How Diarrhea Can Affect Birth Control Pills

Diarrhea can make birth control pills less effective. If you use oral birth control, even one episode of diarrhea can slightly increase your risk of becoming pregnant.

This article explains how diarrhea can negatively affect birth control. It discusses when you should use backup contraception and what birth control options are available.

How Diarrhea Interferes With the Pill

Oral contraceptives work by changing your hormone levels. This stops you from ovulating (releasing eggs from your ovaries). This, in turn, prevents you from getting pregnant. The pill is usually over 99% effective when taken as directed.

Each pill takes two to three hours to be fully absorbed. The active ingredients in the pill work over the course of your menstrual cycle. Their effectiveness depends on taking them on a regular basis. When you miss a dose or two, you may ovulate and become pregnant.

Diarrhea affects how well your body absorbs foods, liquids, and medications. Instead of being taken up into the bloodstream, they are lost in the stool.

Diarrhea and Birth Control Recommendations

The pill may no longer protect against pregnancy if you have severe diarrhea or diarrhea for more than 48 hours. Severe diarrhea means you pass six to eight watery stools in a 24-hour period.

The following Centers for Disease Control and Prevention recommendations pertain to combination pills (containing estrogen and progestin) only.

Chronic Diarrhea and the Pill

Illnesses that cause chronic, repeated bouts of diarrhea can make oral birth control a problem. The most common conditions that cause chronic diarrhea include:

• Diarrhea-predominant IBS (IBS-D)
• Inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease
• Liver disease

These conditions may begin before you started taking birth control or after you have been taking the pill for a while. Chronic diarrhea is also common after gastric bypass surgery and some other procedures involving the intestines.

In addition, chronic diarrhea can come and go. It can recur for months, resolve for a period of time, then return. If you develop chronic diarrhea after reliably using birth control pills for a while, talk to your doctor.

Alternative Methods of Birth Control

The pill is just one form of birth control. Other types of contraception that aren't taken orally and aren't affected by diarrhea include:

• Condoms
• Contraceptive injections
• Diaphragm
• Intrauterine device (IUD)
• Surgical sterilization (permanent birth control procedures)
• Vaginal ring

The vaginal ring, for example, provides the same hormones as the pill. The difference is that the hormones are absorbed through the vaginal wall.

When to Call a Healthcare Provider

If you rely on oral contraception for birth control and have diarrhea, call your healthcare provider. Their advice will be based on:

• How long you've had diarrhea
• How frequent it is
• If you've had sex in the last five days
• What day of your cycle you are on

Your healthcare provider will probably tell you to finish your current pill pack to keep your menstrual cycle on schedule. You may also need to use a different method of birth control until you finish a week of hormone pills or have your period.

Summary

If you take oral contraceptives, be aware that having diarrhea can change their effectiveness. Diarrhea can impact the pill if you have severe diarrhea or diarrhea that lasts for more than 48 hours.

Women with chronic conditions that cause frequent diarrhea may want to consider a different birth control method, such as a vaginal ring or IUD.