Stool tests after two types of weight loss surgery in people with severe obesity
Compares stool test results after sleeve gastrectomy or gastric bypass in adults with severe obesity.
Plain-language title generated from the registry record
Registry title: Stool Analysis After Sleeve Gastrectomy vs Gastric Bypass
Key facts
- Where
- Cairo, EgyptSee the site
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults with severe obesity who are already scheduled for weight loss surgery (sleeve gastrectomy or gastric bypass). Stool and blood samples are taken before surgery and 6 months after.
- Age
- 18 to 60 years
- Sex
- Men and women can join.
- Disease stage
- Severe obesity: BMI of 40 kg/m² or more, or BMI of 35 kg/m² or more with at least one related illness (type 2 diabetes, high blood pressure, abnormal blood fats, osteoarthritis, or sleep apnea).
- Earlier treatment
- People must be scheduled for a first laparoscopic weight loss surgery (sleeve gastrectomy, mini gastric bypass or Roux-en-Y gastric bypass) at Kasr Al-Ainy University Hospitals. Previous weight loss surgery or major bowel or stomach surgery is not allowed.
Main reasons for not taking part
- Previous weight loss surgery or major stomach, bowel or colon surgery
- Chronic kidney disease (eGFR below 60 mL/min/1.73m²) or a past kidney transplant
- Chronic liver disease or liver failure
- Inflammatory bowel disease, celiac disease or chronic pancreatitis
- Antibiotics, probiotics or prebiotics in the 4 weeks before the stool sample
Read by machine on 12 November 2026.
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 18 and 60 years old?
Source: NCT07461610, who can take part
Where in Egypt
- Faculty of Medicine Cairo UniversityCairo, EgyptContact: Mahmoud El Azhary, LecturerTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorTrial details
- Who runs it
- Cairo University
- Trial code
- NCT07461610
- Record updated
- 18 May 2026
- Original description
The goal of this observational study is to learn whether routine stool tests can detect changes in gut function 6 months after two common types of weight loss surgery: sleeve gastrectomy and gastric bypass (including mini gastric bypass and Roux-en-Y gastric bypass). The main questions it aims to answer are:Read full original descriptionShow less
Routine Stool Parameters Six Months After Sleeve Gastrectomy vs. Gastric Bypass: Correlation With Weight Loss and Metabolic Outcomes
The goal of this observational study is to learn whether routine stool tests can detect changes in gut function 6 months after two common types of weight loss surgery: sleeve gastrectomy and gastric bypass (including mini gastric bypass and Roux-en-Y gastric bypass). The main questions it aims to answer are:
Do stool tests show more signs of undigested food or carbohydrate malabsorption after gastric bypass compared to sleeve gastrectomy?
Do signs of gut inflammation in stool (like fecal calprotectin) decrease after surgery, and does this relate to improvements in blood sugar and weight loss?
Can simple stool test results at 6 months predict how much weight a person loses or how well their diabetes improves?
Researchers will compare stool test results between the two surgery groups (sleeve gastrectomy vs. gastric bypass) to see if the type of surgery leads to different changes in gut health.
Participants will:
Provide a stool sample before surgery and again 6 months after surgery
Provide a blood sample at the same time points to measure weight, blood sugar, and cholesterol
Undergo their planned weight loss surgery as part of their regular medical care
Inclusion: Male and female patients aged 18 to 60 years; Body Mass Index (BMI) ≥ 40 kg/m², OR BMI ≥ 35 kg/m² with at least one obesity-related comorbidity (type 2 diabetes, hypertension, dyslipidemia, osteoarthritis, obstructive sleep apnea); Patients scheduled for primary laparoscopic bariatric surgery (either SG or Gastric Bypass [MGB or RYGB]) at Kasr Al-Ainy University Hospitals; Provision of written informed consent.
Exclusion: Previous bariatric surgery or major gastrointestinal surgery (gastric, intestinal, or colorectal resection); Use of antibiotics, probiotics, or prebiotics within 4 weeks prior to stool sample collection (to avoid confounding effects on gut flora); Chronic liver disease (cirrhosis, chronic hepatitis) or liver failure; Chronic inflammatory bowel disease (Crohn's disease, ulcerative colitis), celiac disease, or chronic pancreatitis; Active malignancy or history of chemotherapy/radiotherapy in the past 5 years; Acute gastrointestinal infection at the time of sample collection; Chronic kidney disease (eGFR < 60 mL/min/1.73m²) or previous renal transplant; Age < 18 years or > 60 years; Pregnancy or breastfeeding; Chronic alcohol abuse or substance abuse.