Short answer: Yes, for most people. Once your surgical team moves you past clear liquids, a protein shake is one of the easiest ways to get protein in while food still sounds terrible. It matters more than it seems: in one colorectal study, people who ate at least 60% of their protein needs in the first 3 days went home 4.4 days sooner on average.[4] Your surgical team's instructions come first.

Below you will find how much protein to aim for (with the math), what each stage of recovery usually looks like from the week before surgery to week 6, and where a daily protein packet fits. This article does not replace advice from your surgeon or care team.

What to Know About Colorectal Surgery

Colorectal surgery is different from many other operations. Recovery is not just about the incision healing. It is about getting your gut working again.

For many patients, the scariest part is not the procedure itself. It is the days after:

  • "When will I pass gas or have a bowel movement?"
  • "Why do I feel bloated and nauseated?"
  • "Why does food sound terrible right now?"
  • "How long until I'm back to normal?"

Those fears are valid. After major bowel surgery, the body goes into a high-stress, inflammatory state, and the intestines can slow down for a while (this is called postoperative ileus). The good news is that modern enhanced recovery pathways (ERAS) have changed how this goes, and nutrition is one of the biggest levers you and your family can actually pull.

Below are the most evidence-backed nutrition moves for colorectal surgery, with the numbers, and with the limits of each study stated plainly. For the full before, during and after plan for your operation, see our colorectal surgery nutrition guide.

What the Evidence Says

1) Pre-op carbohydrate drinks can shorten hospital stay a little

The old "nothing after midnight" rule is being replaced in many ERAS programs by clear liquids closer to surgery, including a carbohydrate drink for people who qualify.

A 2025 meta-analysis of 44 trials in major elective non-cardiac surgery found that carbohydrate loading shortened hospital stay by about 0.56 days compared with fasting or a placebo drink.[1] An earlier Cochrane review of 27 trials found a smaller gain, about a third of a day, rated very low-quality evidence, with no change in complication rates.[11] A large network analysis found the benefit came mainly from avoiding a long fast; against plain water, stay was not shorter.[12]

So the honest case is about comfort. In a randomized trial, people who had a carbohydrate drink were less hungry and less anxious while waiting for surgery than people who fasted.[13] If you have diabetes, ask your surgical team before using any carbohydrate drink.[7] Our guide to carb loading drinks before surgery covers timing and how to choose one.

2) Early oral feeding is one of the strongest tools you have

After colorectal surgery, people used to wait days before eating. The evidence now supports early feeding, as your team allows.

A 2021 network meta-analysis of 48 randomized trials (3,614 people) ranked early feeding as the most effective step to reduce ileus after colorectal surgery. Compared with no treatment, it shortened the time to tolerating solid food by about 59 hours and hospital stay by about 2.3 days.[2]

A 2024 review of 34 trials after gut surgery found early eating and drinking may bring the first bowel movement about 1 day sooner and first gas about 0.7 days sooner, with fewer complications (moderate certainty evidence).[3]

Practical translation: the gut often recovers faster when it is gently used rather than "rested" for days, unless your surgeon has a reason to hold food.

3) Protein intake after colorectal surgery is strongly linked to length of stay

Even inside ERAS pathways, most patients struggle to eat enough, especially protein.

In a prospective study of 115 adults having elective colorectal resection, patients ate only 0.33 g of protein per kg a day with conventional care and 0.54 g/kg with ERAS care in the first 3 days, and the ERAS group only got that high because of supplement drinks. Eating at least 60% of protein needs in those 3 days was linked to a 4.4-day shorter stay.[4] This was an observational study, so it shows a link, not proof that protein caused the shorter stay.

To picture it: at 70 kg, 0.54 g/kg is 70 x 0.54 = about 38 g of protein a day. That is roughly a third of what surgical nutrition guidelines estimate you need.

This is a key point for patients and families: you do not need perfect calories early, but you do need protein consistency. After surgery the body breaks down more muscle than usual, and protein is the raw material for:

  • wound healing
  • normal immune function
  • keeping lean muscle (which drives how soon you can walk and get around)
  • repair of the gut lining and other tissue

How much protein do you need after colon surgery?

European surgical nutrition guidelines (ESPEN) estimate about 1.5 g of protein per kg of ideal body weight per day around surgery.[7] Prehabilitation programs for colorectal and esophageal cancer use the same target: in the Fit4Surgery program, counseling plus whey protein raised average intake from 1.20 to 1.61 g/kg a day, and 56.3% of patients reached at least 1.5 g/kg.[8]

Ideal body weight Daily target at 1.5 g/kg One 25 g OptiFuel packet covers 60% of target (first 3 days benchmark)
60 kg (132 lb) 60 x 1.5 = 90 g 25 / 90 = about 28% 90 x 0.6 = 54 g
70 kg (154 lb) 70 x 1.5 = 105 g 25 / 105 = about 24% 105 x 0.6 = 63 g
90 kg (198 lb) 90 x 1.5 = 135 g 25 / 135 = about 19% 135 x 0.6 = 81 g

These are estimates to start a conversation, not your personal prescription. Ask your surgical team or dietitian for your number. If you have kidney disease or have been told to limit protein, talk to your doctor before raising your intake.

4) Oral nutrition supplements (ONS) early after surgery are linked to better outcomes

Randomized trials of routine supplement drinks after colorectal surgery have shown mixed results, often depending on how well nourished people were to begin with and how much they could actually drink. Real-world data points the same way as the protein study above: supplements help most when intake is otherwise low.

A large US hospital database study matched 267 colorectal surgery patients who got a supplement drink before day 3 with 534 who did not. Infectious complications were 6.7% vs 11.8%, and pneumonia, ICU admission and bowel complications were also lower in the supplement group.[5] Two things to keep in mind: it was observational, and several authors worked for or were funded by a supplement maker.

If you have ever watched someone try to meet protein needs through nausea, early fullness and hospital trays, this makes sense: a drinkable protein source gives you a reliable floor while appetite comes back.

5) Immunonutrition is promising, but the evidence is nuanced

"Immunonutrition" means medical formulas that combine arginine, omega-3 fatty acids and nucleotides at set doses. ESPEN says these formulas should be given to malnourished patients having major cancer surgery.[16] For everyone else, the picture is less clear.

  • A 2025 meta-analysis of 10 studies (3,337 colorectal cancer surgery patients) found immunonutrition before surgery was linked to a stay about half a day shorter (0.48 days). Its drops in wound infection and anastomotic leak were not statistically significant, and certainty was low or very low for every outcome.[6]
  • A 2022 multicenter, double-blind trial in 151 well-nourished colorectal cancer patients on an ERAS pathway compared an immunonutrition drink with a standard high-protein drink after surgery. Complications were 32.4% vs 25%, a difference that was not significant.[14]
  • A 2025 randomized trial of 58 colorectal surgery patients found no notable difference in time to first gas, first bowel movement or hospital stay between an immunonutrition drink and a standard supplement before surgery.[15]

Practical takeaway: immunonutrition may help selected patients, especially those who are malnourished or at higher risk, but it is not a universal fix. If your hospital gives you an immunonutrition drink, use it as directed and ask how it fits with any other supplement. OptiFuel is not an immunonutrition formula and has not been tested in colorectal surgery trials. Our Surgical Protocol Kit review compares it side by side with immunonutrition drinks on protein, ingredients and cost.

6) Preparing before surgery (prehabilitation) gives you a head start

Colorectal cancer surgery is one of the best-studied areas for "prehab," meaning exercise and nutrition in the weeks before an operation.

  • In a randomized trial of 77 colorectal cancer patients, a home program of walking and strength exercise, nutrition counseling with protein supplementation and relaxation, started about 4 weeks before surgery, led to 84% vs 62% being back to their starting walking capacity 8 weeks after surgery, compared with starting the same program after surgery. Complications and hospital stay were similar.[9]
  • In a 48-person pilot trial, whey protein with counseling for 4 weeks before surgery was linked to a walking gain of 20.8 m vs 1.2 m with placebo. That difference did not reach statistical significance, and recovery 4 weeks after surgery was similar.[10]

Thrive's protocol starts OptiFuel about 1 week before surgery. Those trials used about 4 weeks, so if your surgery date is further out, ask your team whether a longer prep window makes sense for you.

What to Expect: A Week by Week Timeline

Every recovery is different, and your surgeon's plan comes first (especially around your anastomosis, ileus and when to advance your diet). For many uncomplicated recoveries on an ERAS pathway, the weeks tend to look like this.

When What you do What you may notice
About 1 week before Eat normally unless your team gives you a low-residue diet. If you use the kit, take one OptiFuel packet a day between meals. Walk every day if you can. Nothing dramatic. The goal is to arrive fed, not depleted. In a longer prehab program, counseling plus whey raised daily protein intake from 1.20 to 1.61 g/kg.[8]
Night before Follow your bowel prep and fasting rules first. If your team allows clear fluids, drink 2 OptiCharge packets at bedtime, each mixed in 12 to 16 oz of water (2 x 46 g = 92 g of carbohydrate). In a trial, people who had a carbohydrate drink felt less hungry and less anxious while waiting than people who fasted.[13]
Days 1 to 3 (hospital) Sip clear liquids, then full liquids and soft food as your team allows. Get up and walk. Ask whether chewing gum is OK. Once protein drinks are cleared, a shake is an easy way to add protein. Bloating and nausea are common. Passing gas is a sign the bowel is waking up. Early eating was linked to a first bowel movement about 1 day sooner.[3] Most people eat far too little protein here.[4]
Week 1 at home Eat small amounts several times a day instead of 3 big meals. Try to eat protein every day.[20] Choose lower fiber foods.[18] Ask your surgeon how much to drink. Little appetite is normal for a couple of weeks.[20] Loose or more frequent bowel movements are common at first.[18] Pain with coughing or sneezing can last several weeks.[20]
Weeks 2 to 6 Stay on a lower fiber diet for the first 4 to 6 weeks unless told otherwise.[18] Keep protein steady across the day. Walk a little further each week. Appetite and energy usually return gradually. It can take several weeks to get back to normal activities.[20]
After 6 weeks Bring higher fiber foods back one small item at a time.[18] If your appetite or weight is still down, or chemotherapy comes next, keep a daily protein routine and tell your oncology team what you take. In the prehab trial, 84% of people who prepared before surgery were back to their starting walking capacity by 8 weeks, vs 62% who started after.[9]

What families can do (the recovery "cheat code")

  • Ask every day: "How much protein did they actually get today?" Use the 60% benchmark in the table above.
  • Bring protein options they can tolerate, if the team allows.
  • Track nausea, constipation and loose stools, because if those are not under control, nutrition fails.
  • Know the warning signs below, and call the surgeon if you see them.

Where a Protein Packet Fits, Day to Day

A drinkable protein packet is not magic. It is a practical way to hold a protein floor when chewing a chicken breast is the last thing you want. Here is what using Thrive's kits looks like:

  • Before surgery: The Surgical Protocol Kit includes daily OptiFuel packets, 2 OptiCharge carbohydrate packets for the night before and a shaker. Start about 1 week before surgery.
  • Each day: Mix one OptiFuel packet with 12 to 16 oz of water, milk or non-dairy milk, between meals. Each packet has 25 g of whey protein, 3 g of leucine, vitamin C, vitamin D and small amounts of omega-3 fish oil and turmeric. It is thin enough to drink through a straw, and you can sip it slowly if you feel queasy.
  • After surgery: Restart OptiFuel once your team has you on full liquids or food again, and keep going through recovery. Already had surgery? The Recovery Protocol Kit is the same OptiFuel without OptiCharge.
  • Daily add-on: The Recovery and Strength Mix is the only Thrive product with creatine and arginine. Thrive suggests taking it between lunch and dinner. If cancer treatment is part of your plan, or you have kidney disease, check with your doctors first.

Check first if: you have kidney disease or were told to limit protein; you have diabetes, especially if you use insulin (ask before any carbohydrate drink); you take a blood thinner; you have a milk allergy (OptiFuel is whey-based and contains milk; Thrive suggests the Recovery and Strength Mix alone for people who do not tolerate whey); or you have an ileostomy with high output.

Thrive Protocol makes the products named on this page. Thrive Protocol kits are HSA/FSA eligible, so you can use pre-tax health dollars.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

If You Have a Stoma

Many colorectal operations leave a temporary or permanent colostomy or ileostomy. Your stoma nurse's advice comes first, and ileostomies in particular often come with their own fluid and salt plan. For a colostomy, Memorial Sloan Kettering's patient guide suggests, for the first few weeks:[19]

  • 6 small meals a day instead of 3 large ones, eaten slowly and chewed well
  • 8 to 10 glasses (8 oz each) of fluid a day, about 2 liters
  • mostly bland, lower fiber foods, adding foods back one at a time

Protein needs do not go down because you have a stoma. A thin protein drink can help when solid food feels risky.

Easing Common Problems

Loose stools. A UK hospital factsheet suggests sticking to lower fiber foods, regular meal times, and limiting caffeine, fizzy drinks, alcohol, fruit juice (a small 150 ml glass a day), fatty and spicy foods, and artificial sweeteners.[18] If diarrhea keeps going, contact your surgeon.[20]

Hard stools or no bowel movement. Walk more, and ask your surgeon before using stool softeners, laxatives or fiber products. Pain medicines can be constipating.[20]

Slow bowel recovery in hospital. A Cochrane review of 81 trials found chewing gum after surgery brought first gas about 12.5 hours sooner and first bowel movement about 18 hours sooner in colorectal surgery, though stay was no shorter in studies that already used ERAS care.[17] Ask your team if it is OK for you.

No appetite. Make every mouthful count: add oil, butter or cheese to food, choose full fat over "light" products, eat small high-energy snacks, and avoid drinking right before meals so you do not fill up.[18]

When to Call Your Surgeon

Contact your surgical team if you have any of these after going home:[20]

  • Fever of 101°F (38.3°C) or higher, or a fever that does not go away with acetaminophen
  • A swollen belly, or belly pain that is getting worse and pain medicine does not help
  • Feeling sick to your stomach or throwing up a lot
  • No bowel movement 4 days after leaving the hospital, or bowel movements that suddenly stop
  • Black or tarry stools, or blood in your stools
  • Shortness of breath or chest pain, or swelling or pain in your calves
  • Incision changes: edges pulling apart, drainage, blood, redness, warmth or worsening pain

Frequently Asked Questions

Can I drink protein shakes after bowel resection?

For most people, yes, once your team moves you from clear liquids to full liquids or food. Patients eat very little protein in the first days after colorectal surgery, and supplement drinks were what lifted protein intake in ERAS care.[4] Start slowly, sip rather than gulp, and tell your team if a shake gives you cramps or diarrhea. If you have a stoma or a special diet, ask your surgeon or stoma nurse first.

How much protein do I need after colon surgery?

Surgical nutrition guidelines estimate about 1.5 g per kg of ideal body weight a day.[7] At 70 kg that is 70 x 1.5 = 105 g. Spread it across meals and snacks. Ask your team for your own number, and check with your doctor first if you have kidney disease.

How long should I stay on a low-fiber diet after colon surgery?

Many hospitals advise lower fiber eating for the first 4 to 6 weeks, then bringing higher fiber foods back one small item at a time.[18] It is not meant to be long term unless your doctor or dietitian says so. Your surgeon may give you a different plan, especially if you have a stoma.

Do I need an immunonutrition drink like Impact before colon surgery?

Guidelines recommend immunonutrition formulas for malnourished patients having major cancer surgery.[16] For well-nourished patients on ERAS pathways, recent trials found no clear advantage over standard high-protein supplements.[14][15] If your surgeon prescribes one, use it. OptiFuel is not an immunonutrition formula, so ask your team how the two fit together.

I am losing weight after colon surgery. How do I turn that around?

Little appetite is common for a couple of weeks.[20] Eat small, regular, high-energy snacks, add extra oil, butter or cheese to food, skip "diet" and "light" products, and take short walks, which can help appetite.[18] A daily protein drink can help you keep protein steady. If weight keeps dropping, tell your surgeon or doctor, especially if chemotherapy is next.

Do I need to stop fish oil or turmeric before colon surgery?

OptiFuel contains small amounts of both. In a trial of 1,516 heart surgery patients, fish oil taken around surgery did not increase major bleeding.[21] Thrive's guidance is that there is no need to stop OptiFuel before surgery, but show the label to your surgeon and anesthesia team, and follow their instructions, especially if you take a blood thinner.

Bottom Line

Colorectal recovery is often slowed by the same bottlenecks: ileus, nausea, low intake and weakness. The evidence supports a modern approach:

  • Carbohydrate drinks before surgery (when cleared) make the wait more comfortable and may shorten stay a little.[1]
  • Early feeding helps the gut wake up and is the top-ranked step against ileus.[2]
  • Protein adequacy is tightly linked to length of stay.[4]
  • Oral nutrition supplements are a practical way to keep intake up when appetite is poor.[5]

If you want colorectal recovery to feel less unpredictable, nutrition is one of the clearest levers you can control. For more on eating through recovery after any operation, see what to eat after surgery, and if cancer is the reason for your surgery, our cancer surgery nutrition guide.

Thrive Surgical Protocol Kit with OptiFuel and OptiCharge packets

HSA/FSA eligible. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

References

  1. Sebestyén AR, et al. Preoperative carbohydrate loading reduces length of stay after major elective, non-cardiac surgery when compared to fasting: a systematic review and meta-analysis. Sci Rep. 2025;15(1):19119. PubMed 40450020

  2. Ashcroft J, et al. Reducing ileus after colorectal surgery: a network meta-analysis of therapeutic interventions. Clin Nutr. 2021;40(7):4772-4782. PubMed 34242917

  3. Canzan F, et al. The effect of early oral postoperative feeding on the recovery of intestinal motility after gastrointestinal surgery: a systematic review and meta-analysis of randomized clinical trials. Front Nutr. 2024;11:1369141. PubMed 38818132

  4. Yeung SE, et al. Protein intakes are associated with reduced length of stay: a comparison between Enhanced Recovery After Surgery (ERAS) and conventional care after elective colorectal surgery. Am J Clin Nutr. 2017;106(1):44-51. PubMed 28468890

  5. Williams DGA, et al. Impact of early postoperative oral nutritional supplement utilization on clinical outcomes in colorectal surgery. Perioper Med (Lond). 2020;9:29. PubMed 33029348

  6. McKechnie T, et al. The use of preoperative enteral immunonutrition in patients undergoing elective colorectal cancer surgery: a systematic review and meta-analysis. Colorectal Dis. 2025;27(4):e70061. PubMed 40155502

  7. Weimann A, et al. ESPEN guideline: Clinical nutrition in surgery. Clin Nutr. 2017;36(3):623-650. PubMed 28385477

  8. van Exter SH, et al. Adherence to and efficacy of the nutritional intervention in multimodal prehabilitation in colorectal and esophageal cancer patients. Nutrients. 2023;15(9):2133. PubMed 37432252

  9. Gillis C, et al. Prehabilitation versus rehabilitation: a randomized control trial in patients undergoing colorectal resection for cancer. Anesthesiology. 2014;121(5):937-947. PubMed 25076007

  10. Gillis C, et al. Prehabilitation with whey protein supplementation on perioperative functional exercise capacity in patients undergoing colorectal resection for cancer: a pilot double-blinded randomized placebo-controlled trial. J Acad Nutr Diet. 2016;116(5):802-812. PubMed 26208743

  11. Smith MD, et al. Preoperative carbohydrate treatment for enhancing recovery after elective surgery. Cochrane Database Syst Rev. 2014;(8):CD009161. PubMed 25121931

  12. Amer MA, et al. Network meta-analysis of the effect of preoperative carbohydrate loading on recovery after elective surgery. Br J Surg. 2017;104(3):187-197. PubMed 28000931

  13. Hausel J, et al. A carbohydrate-rich drink reduces preoperative discomfort in elective surgery patients. Anesth Analg. 2001;93(5):1344-1350. PubMed 11682427

  14. Benavides-Buleje JA, et al. Postoperative diet with an oligomeric hyperproteic normocaloric supplement versus a supplement with immunonutrients in colorectal cancer surgery: results of a multicenter, double-blind, randomized clinical trial. Nutrients. 2022;14(15):3062. PubMed 35893914

  15. Pannirselvam M, et al. Effects of preoperative immunonutrition vs standard oral nutrition in patients undergoing colorectal surgery: a randomized controlled trial. World J Gastrointest Surg. 2025;17(9):108127. PubMed 41024777

  16. Weimann A, et al. ESPEN practical guideline: Clinical nutrition in surgery. Clin Nutr. 2021;40(7):4745-4761. PubMed 34242915

  17. Short V, et al. Chewing gum for postoperative recovery of gastrointestinal function. Cochrane Database Syst Rev. 2015;(2):CD006506. PubMed 25914904

  18. University Hospital Southampton NHS Foundation Trust. Eating after bowel surgery (patient factsheet). uhs.nhs.uk

  19. Memorial Sloan Kettering Cancer Center. Diet guidelines for people with a colostomy. mskcc.org

  20. MedlinePlus (US National Library of Medicine). Large bowel resection: discharge. medlineplus.gov

  21. Akintoye E, et al. Fish oil and perioperative bleeding. Circ Cardiovasc Qual Outcomes. 2018;11(11):e004584. PubMed 30571332

This article is for education and does not replace advice from your surgeon or care team. Updated October 21, 2026.