Constipation is a very common side effect of gastric sleeve surgery. During a gastric sleeve procedure, surgeons remove around 80% of your stomach. This drastic change in the anatomy of your stomach causes a number of changes, such as decreased hunger and increased fullness. It can also cause unwanted side effects, such as constipation, diarrhea, and nausea.

Constipation is particularly common in the weeks and months following weight loss surgery. During this time, you may find it difficult to drink as much water or eat as much fiber as you used to. Your diet may also change significantly, and you may be taking medications that increase your risk of constipation.

In this article, you’ll learn what causes constipation after gastric sleeve surgery, how you can prevent it, and what you can do to get things moving again.

How do I know if I’m constipated?

There’s a wide range of “normal” when it comes to your bowel habits. But you might be constipated if you’re having fewer than three bowel movements a week.

Pay attention to the following symptoms of constipation:

  • having infrequent bowel movements
  • passing hard, lumpy, or dry stool
  • straining
  • feeling like you need to go but can’t
  • feeling like you can’t get everything out
  • needing to use a finger to remove stool
  • experiencing cramps, abdomen pain, or bloating
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Constipation following bariatric surgery is normal and common, but is often temporary.

A small 2020 study found that, 6 months out, many people had less constipation than they did before their surgery.

This study followed 124 people with morbid obesity (with an average BMI of around 44) who underwent gastric sleeve surgery. Among those who regularly experienced constipation before surgery, about 45% saw their symptoms improve.

Among people who didn’t have constipation before surgery, about 21% reported experiencing constipation at their 6-month follow-up.

These findings suggest that weight loss surgery can potentially have beneficial effects for people with chronic constipation. However, more research is needed to support these claims.

Is constipation more common after gastric sleeve than other types of weight loss surgery?

Researchers don’t know if gastric sleeve surgery leads to more or less constipation than other types of bariatric surgery. But constipation is a normal side effect of bariatric procedures.

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There are a few reasons why bariatric surgery can make you more constipated than usual.

You digest food differently

Bariatric surgery changes the anatomy of your stomach. Because certain digestive hormones are produced in the stomach, the surgery affects the way that your body digests food. It can also alter the speed at which digested food moves through your body and influence your gut microbiome. These changes can affect your bowel movements.

You don’t eat as much fiber

Fiber plays an important role in the formation of stool. It helps your stool absorb water, which softens it. It also adds bulk to your stool, which helps you pass it more easily. If you’re living on protein drinks and other soft foods, you may not be getting enough fiber to keep you regular.

You drink less water

Stool needs moisture to help it move smoothly. In the weeks following bariatric surgery, you might feel nauseous at times, or just really full. You may feel so full that you find it hard to eat and drink at the same time. You may have also cut out carbonated beverages or other drinks that used to keep you hydrated.

Your diet changes

After gastric sleeve surgery, your stomach is around 80% smaller than it used to be. This means you’ll get full faster, but it also means that every bite counts. You’ll need to eat foods with high nutritional value. Your diet may be significantly different than it was before your surgery, which can affect your bowel habits.

You take pain medications

Immediately following your surgery, you might be given opioid pain relievers. Opioids are notorious for causing constipation.

You’re not moving enough

After your surgery, you should be able to return to your normal level of physical activity right away. However, if you’re feeling nauseous or weak from the changes to your diet, you may not be moving as much as you should. This can have a negative effect on your bowel habits.

If it has been more than 3 days since your last bowel movement, you can try the following over-the-counter (OTC) laxatives:

Follow the manufacturer’s instructions and do not use laxatives for more than 3 weeks. If you don’t have results within 24 hours, be sure to contact your bariatric care team.

Follow these tips to prevent constipation after gastric bypass, gastric sleeve, or other types of bariatric surgery:

  • Stay hydrated: Make sure to drink at least 48 ounces (6 glasses) of water a day. Try drinking small, kid-sized cups of water throughout the day.
  • Eat lots of fiber: Eat high-fiber foods such as fruits and vegetables. Try taking fiber supplements, as needed, to help you get at least 15 grams of fiber a day.
  • Exercise: After surgery, try to take as many short walks as your body allows. Then adopt an exercise routine that incorporates cardio and strength training.

Constipation usually peaks in the early days after bariatric surgery while your body is still adjusting to the smaller stomach size and changed diet. This is called early stage constipation.

Some people develop long-term constipation, which can last months to years after the surgery. If you’re still constipated a month after your surgery, be sure to address this with a doctor.

Constipation after gastric sleeve, and other types of weight loss surgery, is normal and common. It happens for many reasons, including physical changes in your digestive tract, an insufficient amount of fluids and fiber, and a lack of exercise.

However, there are many ways to treat and prevent short-term constipation. Constipation that lasts at least a month after the surgery should be evaluated by a medical professional.