Living without a gallbladder: what changes and what to measure

Living without a gallbladder works perfectly well, and most people notice little after a few months. Your liver keeps making bile; it simply no longer gets stored up and released in one go after a fatty meal. From now on the bile trickles into the gut continuously.

Your gallbladder is a storage tank, not a factory.

That distinction explains almost everything that does and does not change after the operation. And it explains why this topic belongs with a weight-loss course: rapid weight loss is one of the main reasons that operation becomes necessary.

What does your gallbladder actually do?

It stores bile and squeezes it out when fat enters your gut. Your liver makes the bile, the gallbladder concentrates it and holds it. As soon as you eat fat, the bladder contracts and releases a substantial amount at once to help break that fat down.

Without the tank, the portion disappears, not the bile.

The Dutch Maag Lever Darm Stichting accordingly describes the gallbladder as a reservoir. After removal the bile duct takes over part of that function, so in most cases the body adapts within a few months.

Why is fast weight loss the trigger here?

Because with little fat in your food there is barely any prompt left to empty the gallbladder. If the bile sits, it thickens and stones form. That is not a rare consequence but a well-measured risk.

In a Swedish study of 6,640 matched participants, people on a very-low-calorie diet developed symptomatic gallstones at 152 cases per 10,000 person-years against 44 on an ordinary low-calorie diet. Of those cases, 61% ended in surgery (Johansson et al., 2014).

Over three times the risk, for 3 kilos of extra weight loss.

The same applies in principle to anyone eating substantially less on a GLP-1 drug. In STEP 1, participants lost an average of 14.9% of their body weight over 68 weeks (Wilding et al., 2021), a pace that falls in the same territory. The full picture is in the crash diet.

What changes after the operation?

The rhythm of your fat digestion, and surprisingly little beyond it. You can eat normally, you need no special diet, and your liver goes on producing bile. What you lose is the capacity to handle a large quantity of fat in one sitting.

So the first weeks are the hardest, and after that the body adjusts. The Voedingscentrum advises spreading fat across the day as part of a healthy eating pattern, which in this situation also limits the complaints.

Will your bowels give you trouble?

Less often than the story suggests. Chronic diarrhoea after gallbladder removal is treated as a known consequence, but the evidence for it is weaker than its reputation. In a retrospective analysis of stool testing with bile acid quantification, researchers found no higher rate of bile acid diarrhoea after gallbladder removal than in the comparison groups (Gelders et al., 2025).

That is one study and not a final verdict.

It is enough, though, to soften the confident tone this consequence is usually presented with. If complaints persist beyond a few months, that belongs in a conversation with your GP rather than being written off as inevitable. Thuisarts describes when persistent bowel complaints need assessing.

Which blood values are relevant here?

Mainly the vitamins you absorb together with fat. Bile is needed to break fat down, so when the rhythm of fat digestion changes, absorption of the fat-soluble vitamins can shift with it. Vitamin D is the one that matters most in the Netherlands.

Take two people who both had their gallbladder removed a year ago: the first has a vitamin D of 78 nmol/l, the second 24. For the first there is nothing to do. For the second there is, and without measuring neither of them would have known.

Alongside those, ALT and gamma-GT stay useful, because they say something about your liver and bile ducts themselves. A stone left behind in the bile duct shows up there. How those values relate to your pancreas is covered in elevated lipase.

The GLP-1 extended check contains the vitamin and liver values alongside the metabolic picture, assessed by a BIG-registered doctor.

Can you still lose weight without a gallbladder?

Yes, and on one point with less to worry about than before. The risk of gallstones during rapid weight loss disappears, simply because the organ they formed in is no longer there. That removes one of the best-known complications of losing a lot of weight.

It is an odd upside to an unpleasant operation.

Otherwise little changes about the approach. Your food, your exercise and any medication work as they did, and the usual checks stay the same. Do talk to your GP if you want to start a course shortly after the operation.

What I would watch myself

Vitamin D, because that is the value that quietly sinks without you noticing anything. In the Netherlands the baseline is already low in winter, and altered fat digestion is exactly the kind of factor that lands on top of it without producing symptoms.

What strikes me about this topic is how heavily it gets played up.

Read around and you get the impression that life without a gallbladder is a permanent limitation, when for most people it barely registers after a few months. Have your vitamin D and liver values measured a year after the operation, and you will know whether that holds for you too.

References

• Johansson K et al. Risk of symptomatic gallstones and cholecystectomy after a very-low-calorie diet or low-calorie diet in a commercial weight loss program. Int J Obes (Lond). 2014. PMID 23736359
• Gelders F et al. Diagnostic and therapeutic yield of 72h stool collection combined with bile acid quantification: a retrospective analysis. Acta Gastroenterol Belg. 2025. PMID 41083168
• Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021. PMID 33567185
• Maag Lever Darm Stichting, information on the gallbladder and gallstones.
• Thuisarts, information on persistent bowel complaints and when to make contact.
• Voedingscentrum, information on fats in a healthy eating pattern.

Every blood test result includes a professional assessment from a BIG-registered doctor. Discuss your result with your GP before changing anything about your treatment.