Nausea, Dehydration and Constipation After Gastric Sleeve Surgery

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Nausea, Dehydration and Constipation After Gastric Sleeve Surgery

In the first weeks after a gastric sleeve, three common problems are nausea, not drinking enough, and constipation. They are linked: nausea makes it hard to drink, and too little fluid causes more nausea and harder stools. Many cases can be managed at home with steady sipping and a few adjustments. Being unable to keep liquids down is the point to seek care.

Why these three go together

Your new stomach is a narrow tube that is swollen from surgery. It holds very little, so you cannot gulp a glass of water the way you used to. Fluid has to go in a little at a time, all day. If you fall behind, mild dehydration sets in, and dehydration itself causes nausea and tiredness. Feeling sick then makes you drink even less.

The American Society for Metabolic and Bariatric Surgery (ASMBS) advises drinking 64 ounces of fluid or more a day after bariatric surgery to avoid nausea, kidney problems, constipation and fatigue. Ask your surgical team for your own fluid target and diet stages.

Nausea and vomiting

Common causes in the first weeks

Anesthesia and pain medicine in the first days
Drinking or eating too fast, or taking too much at once. MedlinePlus, the National Library of Medicine's patient site, lists vomiting from eating more than the new stomach can hold among the known issues after a sleeve.
Moving to the next diet stage before your stomach is ready
Not chewing enough, once you are on soft foods
Dehydration
Vitamins or other pills taken on an empty stomach, and strong smells or very sweet drinks

What helps

Sip slowly and constantly. Keep a cup or bottle beside you and take a small mouthful every few minutes.
Stop at the first feeling of pressure or fullness. One more sip or bite is often what triggers vomiting.
If a new food does not sit well, go back to the previous stage for a day or two and try again.
If you were prescribed anti-nausea medicine, take it as directed. If you were not, ask your surgical team whether one is right for you. Also ask whether your vitamins can be taken at a different time or in a different form.

Persistent vomiting weeks or months after surgery can point to a narrowing in the sleeve. Our recovery timeline shows what is typical week by week.

Dehydration

How common it is

Dehydration is often given as the reason people return to the emergency department or hospital after bariatric surgery. In an analysis of 256,817 sleeve and gastric bypass patients in the national MBSAQIP database for 2016 and 2017 (Ivanics and colleagues, Surgery for Obesity and Related Diseases, 2019), 9,592 needed outpatient treatment for dehydration within 30 days. It was more frequent after bypass than after a sleeve. People who needed dehydration treatment were also much more likely to be readmitted, with odds 3.7 times higher than those who did not.

Signs to watch for

MedlinePlus lists these signs of dehydration in adults:

Feeling very thirsty, with a dry mouth
Urinating and sweating less than usual
Dark-colored urine
Dry skin
Feeling tired or dizzy

Staying ahead of it

Start sipping as soon as you wake and spread fluids across the whole day. You cannot catch up in the evening.
Count water, broth, sugar-free drinks and protein shakes if your plan allows them. Avoid carbonated and sugary drinks.

If you cannot keep up despite trying, call the office early. Dehydration that does not respond to drinking may need fluids through a vein, so ask where that can be done. If you cannot keep liquids down, or you have any of the emergency signs below, go to an emergency room.

Constipation

Expect fewer bowel movements at first. You are eating very little, much of it liquid, so there is less to pass. Constipation means stools that are hard, painful or difficult to pass, not simply less frequent.

Why it happens

Low fluid intake
Opioid pain medicine
Iron and calcium supplements
A diet that is high in protein and low in fiber in the early stages

What helps

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) recommends fluids, regular physical activity and fiber as the first steps for constipation. After a sleeve that translates into:

Reaching your fluid goal, which matters most
Walking several times a day. MedlinePlus notes that walking a few times daily is advised after a sleeve.
Adding fiber from foods as your diet stage allows, and only with enough fluid
Stopping opioid pain medicine as soon as your pain allows, with your surgeon's agreement

NIDDK describes several kinds of over-the-counter laxatives, including stool softeners, osmotic agents and fiber supplements, and advises using stimulant laxatives only when constipation is severe or other treatments have not worked. Ask your surgical team which product fits your diet stage before you take one, because NIDDK advises drinking plenty of liquids with a fiber supplement, and that can be hard early on.

When to call

Go to an emergency room or call 911 if

You cannot keep any liquids down
You are confused, faint, or have a racing heartbeat or fast breathing. MedlinePlus lists these among the signs of severe dehydration that need immediate care.
You pass little or no urine
You are vomiting blood or passing black stools
You have severe abdominal pain, a swollen abdomen with no gas or stool passing, or fever with a fast heart rate

See the full list on our emergency warning signs page.

Call the office the same day if

You are well short of your fluid goal for a second day
You vomit more than once or twice in a day
Your urine is dark despite your efforts to drink
You have had no bowel movement for several days and feel uncomfortable, or you see blood on the stool

Frequently asked questions

How can I drink 64 ounces when my stomach is so small?

By sipping all day instead of drinking at set times. Sixty-four ounces spread over 16 waking hours is 4 ounces an hour, taken as small mouthfuls, which a healing sleeve can usually manage. It gets easier as swelling goes down. If you are far below your target after the first few days at home, call the office.

Is it normal to feel sick every time I drink plain water?

Many people report that plain water feels heavy or unpleasant for a while after surgery. Changing the temperature or adding a sugar-free flavor often helps, and broth or decaffeinated tea counts toward your goal. If no fluid stays down, that is no longer a taste issue and needs prompt attention.

How many days without a bowel movement is too many after a sleeve?

There is no single number, because intake is so low in the liquid stages. Going a few days is common. What matters is how you feel: bloating, cramping, straining, or hard stools mean it is time to act. Call the office to ask about a stool softener or laxative, and go to an emergency room for severe pain or vomiting that will not stop.

Why do I feel dizzy when I stand up?

Lightheadedness on standing is often a sign that you are low on fluid; MedlinePlus lists dizziness among the symptoms of dehydration. Blood pressure medicine can also become too strong as you lose weight. Sit down, sip fluids, and call the office, especially if you take medicine for blood pressure or diabetes.

Talk with Dr. Davtyan in Rancho Cucamonga

Dr. David G. Davtyan, MD, FACS, FICS, FASMBS, is a bariatric surgeon at Davtyan Medical Weight Loss & Wellness, 8330 Red Oak Street, Suite 201, Rancho Cucamonga, CA 91730. If you are struggling with fluids or nausea after a sleeve, call 909-355-2525 or toll free 877-9-BE-SLIM (877-923-7546); you can also use the contact page for non-urgent questions. The first consultation is complimentary, and Hablamos Español. See the Rancho Cucamonga gastric sleeve guide and foods that are gentle on the stomach after a sleeve.

Nausea, Dehydration and Constipation After Gastric Sleeve Surgery

Nausea, Dehydration and Constipation After Gastric Sleeve Surgery

Why these three go together

Nausea and vomiting

Common causes in the first weeks

What helps

Dehydration

How common it is

Signs to watch for

Staying ahead of it

Constipation

Why it happens

What helps

When to call

Go to an emergency room or call 911 if

Call the office the same day if

Frequently asked questions

How can I drink 64 ounces when my stomach is so small?

Is it normal to feel sick every time I drink plain water?

How many days without a bowel movement is too many after a sleeve?

Why do I feel dizzy when I stand up?

Talk with Dr. Davtyan in Rancho Cucamonga

Sources

More in the Gastric Sleeve in Rancho Cucamonga guide

Understanding the sleeve

Weighing your options

Getting care in Rancho Cucamonga

Adult BMI Calculator

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Rancho Cucamonga

South Coast Lap-Band

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