# Right-Sided Colon Surgery and Slower Bowel Recovery: What Patients Need to Know

This study of 384 patients who underwent colon removal surgery (colectomy) found that those who had a **right-sided colectomy experienced significantly slower return of normal bowel function** compared to those who had a left-sided procedure. Specifically, patients in the right-sided group passed their first stool a full day later (postoperative day 2 vs. day 1) and had a higher rate of postoperative ileus (a temporary halt in bowel function) — 17% vs. 14% overall, and a statistically significant 15% vs. 7% when only minimally invasive (laparoscopic) procedures were analyzed. Despite these differences in bowel recovery, hospital stay duration and overall complication rates were similar between the two groups, suggesting that while right-sided surgery poses unique recovery challenges, patients can still expect comparable overall outcomes when managed within a structured enhanced recovery program.

# Right-Sided Colon Surgery and Slower Bowel Recovery: What Patients Need to Know

## Table of Contents

- Key Points
- Background: Why This Research Matters
- How the Study Was Conducted
- Key Findings: What the Researchers Discovered
- Understanding the Results: Why Right-Sided Surgery May Be Different
- Study Limitations: What This Research Couldn't Prove
- Recommendations for Patients
- Frequently Asked Questions
- Source Information

## Key Points

- In a study of 384 colectomy patients, right-sided surgery led to first stool about one day later than left-sided surgery (median day 2 vs. day 1).
- Postoperative ileus occurred in 17% of right-sided and 14% of left-sided patients overall; among laparoscopic cases, rates were 15% vs. 7%, a significant difference.
- Anastomotic leakage was the strongest risk factor for ileus (odds ratio 58), followed by poor physical function, conversion to open surgery, and lack of oral bowel preparation.
- The study could not determine why right-sided colectomy slows bowel recovery; findings are from one center and may not apply everywhere.

## Background: Why This Research Matters

Over the past 20 years, elective colorectal surgery has experienced two major advancements: the introduction of **laparoscopic (minimally invasive) surgery** and the implementation of **Enhanced Recovery After Surgery (ERAS) programs**. ERAS consists of a set of evidence-based guidelines designed to minimize the body's stress response to surgery, reduce organ dysfunction, and promote rapid recovery. These programs have been shown to be safe, cost-effective, and associated with faster postoperative recovery, fewer complications, and shorter hospital stays.

Surgical removal of the colon (colectomy) can be performed on either the right side or the left side of the large intestine. Right-sided colectomy (removing the first portion of the colon, called the ascending colon) is often performed for cancers or growths (polyps) in that area. Left-sided colectomy (removing the descending colon or sigmoid colon) is frequently done for diverticular disease or cancers located on the left side.

It has long been believed by surgeons that recovery after right-sided colectomy is more challenging and prolonged compared to left-sided resection. This slower recovery is partly attributed to a higher incidence of **postoperative ileus (POI)** — a condition where the bowel temporarily stops functioning properly after surgery, causing nausea, vomiting, abdominal swelling, and the inability to pass gas or stool.

POI occurs in 10% to 17% of cases and is among the most common complications following abdominal surgery. Recent studies have identified right-sided colon resection as a risk factor for developing POI. However, the reasons behind slower functional recovery and higher POI rates in right-sided procedures remain poorly understood. This study was designed to compare bowel function recovery between right-sided and left-sided colectomies within a fully implemented ERAS program, and to identify risk factors for POI.

## How the Study Was Conducted

This was a **retrospective single-center study** conducted at the General Surgery Department of the Martini General Hospital in Groningen, the Netherlands. The researchers used data from a prospective ERAS database, covering all patients who underwent elective (planned, non-emergency) colectomy between **January 2017 and May 2020**.

Patients were divided into two groups based on the type of surgery they received:

-
**Right-sided colectomy group:** patients who underwent right hemicolectomy or ileocecal resection (removal of the end of the small intestine and beginning of the large intestine)
-
**Left-sided colectomy group:** patients who underwent left hemicolectomy or sigmoid resection

Patients who had a transversectomy (removal of the middle portion of the colon) were categorized as right or left based on which flexure (the bend where the colon turns) the resection was closest to. All surgeries were performed or supervised by board-certified surgeons. The standard approach was laparoscopy, unless there were medical reasons against it. The anastomosis (reconnection of the bowel ends) was created using hand-sewing, stapling, or a combination of both.

The study measured several outcomes:

-
**ERAS protocol compliance** — assessed as a yes/no answer for each of the 24 items in the protocol
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**Functional recovery** — time to first passage of gas (flatus), time to first bowel movement (stool), and ability to tolerate solid food, all measured in postoperative days (POD)
-
**Postoperative ileus** — defined as the need for a nasogastric tube (a tube inserted through the nose into the stomach) due to persistent nausea, vomiting, and abdominal distension
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**Clinical outcomes** — complications, adverse events, and length of hospital stay. Complications were graded using the Clavien-Dindo classification system, a five-point severity scale

A **post hoc analysis** (an additional analysis performed after the main results were collected) was conducted including only patients who underwent elective laparoscopic surgeries, because open surgery is known to be associated with delayed functional recovery.

Statistical analysis was performed using RStudio version 1.2.5042. Continuous variables were expressed as median (interquartile range) or mean ± standard deviation, depending on their distribution. A p-value of less than 0.05 was considered statistically significant. A total of **48 patients were excluded** from the risk factor analysis because they had incomplete data (a method called listwise deletion).

One important detail: the hospital had a specific protocol deviation regarding oral bowel preparation. Patients undergoing right colectomy did not fully adhere to this protocol item because of differences in intestinal content consistency, while those undergoing left colectomy received standard oral bowel preparation. As we'll see, this affected the ERAS compliance numbers.

## Key Findings: What the Researchers Discovered

### Who Was in the Study?

A total of **384 patients** were included in the analysis. Of these, **58% (223 patients) underwent right-sided colectomy**, while **42% (161 patients) had left-sided resection**.

Several differences existed between the two groups at the start of the study:

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**Age:** Right-sided patients were older — median 71 years (range 65–77) vs. 69 years (range 60–73) for left-sided patients (p < 0.001)
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**Gender:** 42% of right-sided patients were male vs. 58% of left-sided patients (p = 0.002)
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**BMI:** Left-sided patients had a significantly higher body mass index — 28 kg/m² vs. 26 kg/m² for right-sided patients (p = 0.001)
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**Underlying disease:** Right-sided patients more often had malignancy (cancer) — 85% vs. 75% — and more often had other benign conditions including polyps (10% vs. 3%). In contrast, diverticular disease was seen only in left-sided patients, representing 19% of surgical indications in that group (p < 0.001)

Other factors were similar between the groups, including smoking rates (14% in both), alcohol use, ASA scores (a measure of overall health before surgery), diabetes, heart disease, and lung disease. Only 2% of patients overall had a WHO performance score of 2 or higher (indicating limited physical activity), suggesting that most patients were in relatively good health before surgery.

### Surgical Details: What Happened During the Operations

The two groups differed significantly in several surgical characteristics:

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**Surgical approach:** Laparoscopy was used more often for right-sided colectomies — 82% vs. 72% for left-sided procedures. Conversion to open surgery (switching from laparoscopy to a larger incision) occurred in 5% of right-sided vs. 9% of left-sided procedures. Open surgery (laparotomy) was performed in 13% of right-sided vs. 19% of left-sided cases (p = 0.07). Although this difference was not statistically significant, it trended toward more open/converted surgery in the left-sided group.
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**Duration of surgery:** Left-sided operations took significantly longer — median of 169 minutes (range 130–209) vs. 125 minutes (range 97–157) for right-sided operations (p < 0.001)
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**Intraoperative blood loss:** Left-sided surgeries caused more bleeding — median 0 ml in both groups, but with a wider range in the left-sided group (0–200 ml vs. 0–50 ml) (p < 0.001)
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**New stoma (colostomy bag):** Only 1 patient (0%) in the right-sided group needed a new stoma vs. 4 patients (2%) in the left-sided group (p = 0.17)
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**Opioid use:** Similar in both groups — 77% of all patients received long-acting systemic opioids, 19% received short-acting opioids, and 4% received none

### ERAS Compliance: Following the Recovery Protocol

Compliance with the ERAS protocol was **significantly higher in patients undergoing right-sided colectomy: 70% vs. 66%** for left-sided patients (p < 0.001). This difference was driven mainly by the preoperative phase, where the right-sided group achieved nearly 100% compliance compared to 84% in the left-sided group (p < 0.001). This was due to the institutional decision to skip oral bowel preparation in right-sided colectomy patients.

### Bowel Functional Recovery: The Core Finding

The study's central finding was that **bowel function returned more slowly after right-sided colectomy**:

-
**First passage of gas (flatus):** Both groups passed gas at a median of 1 postoperative day, but the right-sided group had a wider range (1–2 days) compared to left-sided (1–1 day) (p < 0.001)
-
**First passage of stool:** Right-sided patients had their first bowel movement at a median of **2 postoperative days** (range 1–3), while left-sided patients had theirs at a median of **1 postoperative day** (range 1–2) — a statistically significant difference (p < 0.001)
-
**Tolerance of solid food:** Both groups tolerated solid food at a median of 0–1 postoperative day (p = 0.48), meaning there was no significant difference in when patients could eat normally again

### Postoperative Ileus: A Key Complication

In the overall analysis:

-
**37 patients (17%)** who underwent right-sided colectomy developed POI
-
**22 patients (14%)** who underwent left-sided colectomy developed POI
- This difference was **not statistically significant** (p = 0.5)

However, when the researchers performed the post hoc analysis limited to **laparoscopic surgeries only**, the picture changed dramatically:

-
**27 patients (15%)** in the laparoscopic right-sided group developed POI
-
**8 patients (7%)** in the laparoscopic left-sided group developed POI
- This difference **was statistically significant** (p = 0.04)

In the laparoscopic subgroup, the time to first stool was also confirmed to be slower after right-sided surgery (median 2 days vs. 1 day, p < 0.001). The researchers explained that the higher rate of open and converted surgeries in the left-sided group likely *increased* the POI rate in that group, masking the true difference in the overall analysis. When only laparoscopic procedures were compared, the natural advantage of left-sided surgery became clear.

### Complications and Hospital Stay

Despite the differences in bowel recovery, **overall outcomes were similar between the groups**:

-
**Complications during the primary (first) hospital stay:** 98 right-sided patients (44%) vs. 59 left-sided patients (37%) experienced complications or adverse events (p = 0.18) — a difference that was not statistically significant
-
**Reoperations:** 19% in both groups (p > .999)
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**Intensive care admissions:** 10% of right-sided vs. 7% of left-sided patients (p = 0.66)
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**Anastomotic leakage** (a leak where the bowel was reconnected) was the most common reason for reoperation in both groups — accounting for 42% of reoperations in the right-sided group and 36% in the left-sided group
-
**Length of hospital stay:** Median 4 days (range 2–6) for right-sided vs. 3 days (range 2–6) for left-sided patients (p = 0.5) — not statistically significant
-
**Readmissions within the study period:** 7% for right-sided vs. 10% for left-sided patients (p = 0.44)

### Risk Factors for Postoperative Ileus

The researchers identified **six independent risk factors** for developing POI using multivariate analysis (a statistical technique that accounts for multiple factors simultaneously):

1.
**Anastomotic leakage** — the strongest predictor, with an odds ratio (OR) of 58.22 (95% confidence interval [CI] 13.08–421.14, p < 0.001). This means patients with a leak had a 58 times higher risk of POI.
1.
**WHO performance score ≥ 2** — OR 16.33 (CI 1.61–168.91, p = 0.01). Patients with poorer physical function before surgery had a 16 times higher risk.
1.
**Conversion to open surgery** — OR 3.99 (CI 1.24–11.69, p = 0.02). Patients whose laparoscopic procedure was converted to open surgery had 4 times the risk.
1.
**Absence of oral bowel preparation** — OR 3.93 (CI 1.73–10.01, p = 0.002). Not receiving oral bowel preparation was associated with nearly 4 times the risk.
1.
**Laparotomy (planned open surgery)** — OR 3.19 (CI 1.29–7.65, p = 0.01). Open surgery carried over 3 times the risk of POI compared to laparoscopy.
1.
**ASA score ≥ 3** — interestingly, this was associated with a *lower* risk of POI (OR 0.27, CI 0.08–0.76, p = 0.02), meaning patients classified as higher surgical risk (ASA III–IV) paradoxically had fewer instances of POI in this study.

Other factors such as male gender, age over 70, BMI over 25, diabetes, heart disease, lung disease, presence of metastasis, preoperative malnutrition, new stoma, intraoperative blood loss over 500 ml, and surgery lasting more than 180 minutes did not reach statistical significance as independent risk factors.

## Understanding the Results: Why Right-Sided Surgery May Be Different

This study confirms what many surgeons have long suspected: **recovery of bowel function is delayed after right-sided colectomy compared to left-sided colectomy**. The finding aligns with recent literature reports. Several factors may explain this difference.

First, the study found a POI rate of 15% in the laparoscopic right-sided group. This coincides with findings from other studies and a systematic review by Wolthuis et al., which reported POI prevalence in the general literature at closer to 10%. The authors note that the Wolthuis review had limitations, including the use of various definitions of ileus and reliance on low-quality data series.

Second, the two groups had different baseline characteristics. Right-sided patients were older and more often female, and had more cancer diagnoses. Left-sided patients had higher BMI, longer operations, more blood loss, and more open/converted surgeries. Each of these factors can influence recovery in different ways.

The researchers believe the higher rate of open and converted operations in the left-sided group likely **raised the POI rate in that group**, making the two groups appear more similar than they truly are. This is why the laparoscopic-only analysis is so revealing: when this "noise" was removed, the significantly higher POI rate after right-sided surgery became apparent.

Another important observation: even though right-sided patients had slower bowel function recovery, their hospital stay was not longer (4 days vs. 3 days, p = 0.5). The authors suggest that the higher complication rate in the left-sided group (possibly tied to more conversions and open surgeries) offset any potential advantage from faster bowel recovery.

The study also found a strong positive correlation between **anastomotic leakage and POI**, consistent with several other studies. Peters et al. have suggested that inflammation may serve as the biological mechanism connecting these two complications — the leak causes inflammation in the abdominal cavity, which in turn disrupts normal bowel contractions.

Regarding the paradoxical finding that ASA ≥ 3 was associated with lower POI risk, the authors offer an explanation: this patient cohort was generally quite healthy, with only 6 patients (2%) having WHO scores of 2 or higher and 75 patients (20%) having ASA scores of III–IV. The relatively high level of fitness and preoperative optimization in this group may have influenced the results, contradicting findings from other studies that link higher ASA scores to increased POI risk.

## Study Limitations: What This Research Couldn't Prove

It's important to understand the limitations of this study when interpreting the results:

-
**Retrospective design:** The study used data collected from a database rather than a randomized controlled trial. This means the researchers could not control for all variables, and there may be unmeasured factors influencing the results.
-
**Subjective definition of POI:** Using nasogastric tube insertion as the definition of POI has limitations. A tube can be inserted quickly after only one episode of vomiting, making the definition somewhat subjective and potentially varying between clinicians.
-
**Differences in disease types:** The groups were not equivalent — right-sided patients had more cancer, while left-sided patients had more diverticular disease. These different underlying conditions may influence recovery in ways not fully captured by the analysis.
-
**Single center:** The study was conducted at one hospital, which may limit how well the findings apply to other institutions with different protocols.
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**Protocol deviation:** The institutional decision to skip oral bowel preparation in right-sided colectomies was a deviation from standard ERAS protocol and may have influenced both compliance rates and POI risk.
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**Cause remains undetermined:** Although the study found that right-sided colectomies are associated with slower bowel recovery and higher POI, it could not determine *why* this is the case. The cause requires further investigation.
-
**48 patients excluded:** The risk factor analysis excluded patients with incomplete data, which could introduce selection bias.

## Recommendations for Patients

Based on this research, here is what patients should know and consider:

1.
**If you're having a right-sided colectomy, expect a slightly slower return of bowel function.** It's normal for your first bowel movement to come a day later than it would after left-sided surgery. This should not cause alarm, provided your surgical team is monitoring you appropriately.
1.
**Ask about laparoscopic surgery.** This study confirms that laparoscopy is associated with faster bowel recovery and lower POI rates. If you are a candidate for minimally invasive surgery, it may offer you better outcomes.
1.
**Follow your surgeon's bowel preparation instructions.** The study found that lack of oral bowel preparation was associated with an increased risk of POI (OR 3.93). However, the right-sided patients in this study were the ones who skipped it, so it's unclear whether this is a true cause-and-effect relationship or simply reflects other differences between the groups.
1.
**Understand that complications affect recovery.** Anastomotic leakage was the strongest risk factor for POI. While leakage is relatively uncommon, its impact on recovery is substantial. Promptly reporting symptoms like abdominal pain, fever, or unusual drainage to your care team is essential.
1.
**Be aware of your overall health status.** A higher WHO performance score (meaning poorer physical function) before surgery was a strong predictor of POI. If you can improve your physical conditioning before surgery, this may help your recovery.
1.
**Don't expect complications to lengthen your hospital stay.** Reassuringly, the slower bowel recovery after right-sided surgery did not translate into a longer hospital stay — both groups went home around day 3–4. ERAS programs are designed to get you home safely regardless of which side of the colon is operated on.
1.
**Ask your surgeon about ERAS compliance.** Patients who fully participate in ERAS protocols tend to have better outcomes. This includes early mobilization (getting out of bed soon after surgery), minimizing opioid use, and starting to eat when your surgeon says it's safe.

Ultimately, the most important message from this study is that **right-sided and left-sided colectomies are different procedures with different recovery patterns**. The slower bowel recovery after right-sided surgery does not mean a worse overall outcome. With a well-implemented ERAS program and an experienced surgical team, patients can expect safe recovery from either procedure.

The authors conclude that a more conservative early postoperative feeding strategy may be advisable for right-sided colectomy patients, and greater emphasis should be placed on optimizing adjustable risk factors associated with POI. Further research is needed to understand the mechanisms behind the slower recovery and to develop side-specific ERAS guidelines.

## Frequently Asked Questions

### Will my bowel function return more slowly after right-sided colon surgery?

In a study of 384 patients, those who had right-sided colectomy passed their first stool about one day later than left-sided patients (median day 2 versus day 1). Passing gas was also slightly slower. This delay is expected and is not necessarily a sign of a problem, as long as your surgical team is monitoring you.

### What is postoperative ileus and how common is it after colectomy?

Postoperative ileus is a temporary halt in bowel function, causing nausea, vomiting, abdominal swelling, and inability to pass gas or stool. In the overall study of 384 patients, 17% of right-sided and 14% of left-sided colectomy patients developed it. When only laparoscopic surgeries were analyzed, the rates were 15% versus 7%, a significant difference.

### I'm scheduled for a right-sided colectomy for colon cancer — when should I get a second opinion about whether the surgery and approach are right for me?

A second opinion is worth considering before a right-sided colectomy, particularly to review whether laparoscopic surgery is appropriate, since laparoscopy is linked to faster bowel recovery and lower rates of postoperative ileus than open surgery. Bowel function returns about a day later after right-sided than left-sided colectomy, and ileus occurred in 15% versus 7% of laparoscopic cases. A second opinion can also address bowel preparation instructions and whether adjustable risk factors such as physical conditioning should be optimized beforehand. Diagnostic Detectives Network provides independent expert second opinions.

## Source Information

**Original Article Title:** Right-sided colectomies are associated with slower bowel functional recovery compared to left-sided colectomies

**DOI:** [10.24911/IJMDC.51-1734605210](https://doi.org/10.24911/IJMDC.51-1734605210)

**Authors:** Rakan Mal, Henriëtte Smid-Nanninga, Ahmed Abdullah, Nouf Almalki, Baraa Tabbakh, Annette Olieman, Hans D. de Boer

**Journal:** International Journal of Medicine in Developing Countries, 2025;9(2):330–338

**DOI:** 10.24911/IJMDC.51-1734605210

**Publication Dates:** Received: December 19, 2024 | Accepted: January 27, 2025

This patient-friendly article is based on peer-reviewed research. The original study was approved by the institutional medical ethics committee of Martini General Hospital (MEC-2020-027).


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