A Complete Patient's Guide to Colonoscopy in Nigeria
Table of Contents
If your doctor has recommended a colonoscopy, or if you are experiencing symptoms such as blood in your stool, persistent changes in bowel habits, unexplained abdominal pain, or you are due for a routine colorectal cancer screening, this guide will walk you through everything you need to know.
Colonoscopy is the most important and accurate procedure available for examining the large intestine, detecting colorectal cancer at its earliest and most treatable stage, and removing potentially pre-cancerous polyps before they develop into cancer.
At Redus Center for Digestive Health in Lagos, our specialists perform colonoscopy using high-definition equipment with a thorough, patient-centred approach that prioritises your comfort, safety, and peace of mind.
What is a Colonoscopy?
A colonoscopy is a minimally invasive medical procedure that allows a gastroenterologist to directly examine the entire inner lining of the large intestine (colon) and rectum. It is typically used to diagnose and treat various gastrointestinal issues, including colon cancer, polyps, and inflammatory bowel diseases.
A long, thin, flexible tube called a colonoscope is gently introduced through the rectum and carefully advanced through the full length of the colon — all the way to where the large intestine meets the small intestine at the ileocaecal valve, and sometimes a short distance into the terminal ileum.
At the tip of the colonoscope is a high-definition camera that transmits real-time images to a monitor, allowing the physician to inspect the mucosal lining of the colon in detail. The colonoscope also has a working channel through which instruments can be passed — allowing biopsy forceps, polypectomy snares, and other tools to be introduced to take tissue samples or perform treatments during the same procedure.
Colonoscopy is unique among diagnostic investigations of the colon in that it is simultaneously diagnostic and therapeutic. A suspicious polyp identified during a screening colonoscopy can often be removed on the spot, preventing it from ever developing into colorectal cancer. This makes colonoscopy not only the gold standard for colorectal cancer screening but one of the most powerful tools in cancer prevention available in medicine today.
Understanding the Large Intestine
To understand the full scope of what a colonoscopy examines, it helps to know the anatomy of the large intestine. The colon is approximately 1.5 metres long and frames the abdominal cavity. It is divided into several sections, each of which the colonoscopist carefully examines:
- Rectum: The final 12 to 15 cm of the large intestine, connecting to the anus. The colonoscope enters here and is progressively advanced through the remaining sections.
- Sigmoid colon: An S-shaped section in the lower left abdomen, immediately above the rectum. This is a common site for polyps and diverticular disease.
- Descending colon: Runs down the left side of the abdomen.
Transverse colon: Crosses horizontally across the middle of the abdomen from left to right. - Ascending colon (right colon): Runs up the right side of the abdomen from the caecum.
- Caecum: A pouch at the junction of the small and large intestines in the lower right abdomen. The appendix is attached here.
Reaching the caecum (confirming a complete examination) is an important quality marker in colonoscopy. A colonoscopy that does not reach the caecum may miss lesions in the right colon, where cancers can grow silently without causing obvious symptoms. At Redus, our endoscopists achieve high caecal intubation rates, ensuring thorough and complete examinations for every patient.
Why is a Colonoscopy Performed?
Colonoscopy is one of the most widely performed procedures in gastroenterology and is recommended across a broad range of clinical situations. At Redus Center for Digestive Health, our specialists commonly recommend colonoscopy for the following reasons:
- Colorectal Cancer Screening
Colorectal cancer (cancer of the colon or rectum) is one of the most common and most preventable cancers globally. It typically develops slowly over many years from small, benign growths called polyps. Regular colonoscopy screening allows these polyps to be detected and removed before they progress to cancer. Because of this, colonoscopy is genuinely a cancer-preventing investigation, not merely a cancer-detecting one.
Screening colonoscopy is recommended for average-risk individuals from the age of 45. Those with a family history of colorectal cancer or polyps, or with personal risk factors such as inflammatory bowel disease, are advised to begin screening earlier and undergo surveillance at more frequent intervals. If no polyps or abnormalities are found in a well-prepared colon, a repeat colonoscopy is typically not needed for 10 years. - Investigation of Rectal Bleeding
Blood in or on the stool is one of the most common reasons for referral for colonoscopy. While rectal bleeding is frequently caused by benign conditions such as haemorrhoids (piles) or anal fissures, it can also be a sign of colorectal polyps, inflammatory bowel disease, diverticular disease, or colorectal cancer. Colonoscopy allows the source of bleeding to be identified directly and, in many cases, treated in the same session. This can be by injecting or cauterising a bleeding vessel, or by banding haemorrhoids. - Change in Bowel Habits
A persistent and unexplained change in bowel habits, such as new-onset diarrhoea, constipation, or alternating between the two, particularly in patients over 40 or in those with additional risk factors, warrants colonoscopic evaluation. Such changes can be caused by colorectal cancer, inflammatory bowel disease, irritable bowel syndrome, or other colonic pathology. - Iron Deficiency Anaemia
Iron deficiency anaemia in adults, particularly in men and post-menopausal women, in whom dietary deficiency and menstrual loss are less likely explanations, should prompt investigation of the gastrointestinal tract for a source of occult (hidden) blood loss. Colonoscopy is the key investigation for the lower GI tract in this setting, and is often performed alongside upper endoscopy. - Abdominal Pain and Bloating
Persistent lower abdominal pain, cramping, or significant bloating, particularly when accompanied by changes in bowel habit or rectal bleeding, may indicate colonic pathology. Colonoscopy provides a direct assessment of the colonic mucosa and can identify causes such as Crohn’s disease, diverticular disease, colitis, or tumour. - Diagnosis and Monitoring of Inflammatory Bowel Disease (IBD)
Inflammatory bowel disease — which includes Crohn’s disease and ulcerative colitis — causes chronic inflammation of the gastrointestinal tract and requires accurate diagnosis and ongoing monitoring. Colonoscopy with biopsy is the principal tool for diagnosing IBD, assessing the extent and severity of disease activity, and monitoring response to treatment. Patients with long-standing IBD also require regular colonoscopic surveillance for dysplasia and colorectal cancer, as their risk is elevated compared to the general population. - Polyp Surveillance
Patients who have previously had colorectal polyps removed require follow-up colonoscopy at intervals determined by the number, size, and type of polyps found. This surveillance programme is designed to detect and remove any new polyps before they have the opportunity to become cancerous, significantly reducing long-term colorectal cancer risk. - Diverticular Disease
Diverticulosis is a common condition in which small pouches (diverticula) form in the wall of the colon, particularly in the sigmoid colon. Diverticulitis (inflammation of these pouches) can cause significant pain and complications. Colonoscopy is used to assess the extent of diverticulosis, evaluate complications such as stricturing or fistula, and exclude other pathology including cancer, particularly after an acute episode has resolved. - Family History of Colorectal Cancer or Polyposis Syndromes
Individuals with a first-degree relative (parent, sibling, or child) diagnosed with colorectal cancer or significant colonic polyps are at higher-than-average risk and are advised to begin colonoscopic screening earlier — typically at age 40, or 10 years before the age at which the youngest affected family member was diagnosed, whichever comes first. Those with hereditary polyposis syndromes such as familial adenomatous polyposis (FAP) or Lynch syndrome require intensive surveillance from a young age. - Unexplained Weight Loss
Unintentional weight loss, when not explained by obvious dietary or metabolic factors, requires thorough investigation including assessment of the gastrointestinal tract. Colonoscopy is part of the workup when lower GI pathology — including colorectal malignancy — is suspected.
Therapeutic Uses of Colonoscopy
Beyond diagnosis, colonoscopy enables a range of therapeutic interventions to be performed during the same procedure, avoiding the need for separate surgical treatment in many cases:
- Polypectomy
The removal of polyps during colonoscopy is one of the most important procedures in preventive gastroenterology. Small polyps are removed using biopsy forceps or a cold snare (a wire loop tightened around the polyp base). Larger polyps are removed using hot snare polypectomy with electrocautery. The removed polyp is sent for histological analysis to determine its type and whether complete removal has been achieved.
Polypectomy directly interrupts the adenoma-carcinoma sequence — the pathway from benign polyp to colorectal cancer — and is estimated to prevent a significant proportion of colorectal cancers from ever developing. - Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD)
For larger, flat, or sessile (non-pedunculated) polyps and early-stage colorectal cancers confined to the superficial layers of the bowel wall, more advanced resection techniques can be employed. EMR involves injecting fluid beneath the lesion to lift it away from the underlying muscle layer before cutting it free with a snare.
ESD is a more technically complex technique that allows precise dissection of even larger lesions in a single piece (en bloc), reducing the risk of incomplete resection. These techniques offer curative treatment for selected early colorectal cancers without the need for surgery. - Treatment of Lower GI Bleeding
When active bleeding in the colon is identified — from a diverticular vessel, an angiodysplasia, or a post-polypectomy site — colonoscopy allows immediate treatment. Techniques include injection of adrenaline, application of haemostatic clips, argon plasma coagulation (APC), and thermal contact treatment. Endoscopic haemostasis avoids the need for emergency surgery in the majority of cases. - Colonic Stenting
In patients with colorectal cancer causing acute obstruction of the bowel, a self-expanding metal stent can be placed across the obstruction during colonoscopy, restoring luminal patency and relieving the obstruction. This can be used as a bridge to elective surgery — allowing the patient to be optimised before a planned operation — or as a definitive palliation in patients with incurable disease. - Stricture Dilation
Narrowings (strictures) of the colon caused by Crohn’s disease, post-surgical scarring, or diverticular disease can sometimes be dilated during colonoscopy using a balloon dilator, avoiding or deferring surgery.
Preparing for a Colonoscopy
Preparation is crucial for a successful colonoscopy. Here are the steps you need to follow:
Bowel Preparation
Bowel preparation is the process of clearing the colon of all stool before the procedure. It is arguably the most critical factor in the success of a colonoscopy. A poorly prepared colon means residual stool can obscure lesions, leading to missed polyps or cancers, and may require the procedure to be repeated. At Redus, we invest time in explaining the preparation process thoroughly because a well-prepared patient directly leads to a better outcome.
Dietary Restrictions Before Procedure
Typically beginning 3 to 5 days before the procedure, you will be advised to follow a low-residue (low-fibre) diet. This means avoiding high-fibre foods such as wholegrains, raw vegetables, fruits with seeds or skins, nuts, and legumes. The aim is to reduce the volume of stool in the colon before the laxative preparation begins.
The day before the colonoscopy, you will switch to a clear liquid diet — water, clear broths, strained juices, black tea or coffee without milk, and clear carbonated drinks. No solid food is permitted. Fluids should be taken generously throughout the day to maintain hydration.
Bowel Preparation Solution
You will be prescribed a bowel preparation solution (laxative) that must be taken as instructed — typically in the evening before the procedure, or in a split-dose regimen with one dose the evening before and another on the morning of the procedure. Split-dose preparation, where the second portion is taken 4 to 6 hours before the procedure, is associated with better colon cleansing and higher polyp detection rates, and is the preferred approach at Redus.
The preparation solution works by drawing large volumes of fluid into the bowel, producing a series of watery bowel motions that clear the colon. Most patients find this the most challenging part of the process. The key is to drink the preparation slowly but steadily as directed, stay well hydrated with additional clear fluids, and remain close to a toilet during the preparation period.
The preparation is complete when the bowel motions are clear or pale yellow with no solid matter.
Medication
Inform your gastroenterologist and care team about all medications you take. Important considerations include:
- Blood-thinning medications (anticoagulants and antiplatelets such as warfarin, clopidogrel, aspirin, and rivaroxaban): These may need to be paused before the procedure, particularly if polypectomy is anticipated, to reduce the risk of post-polypectomy bleeding. Your doctor will advise on precise timing.
- Diabetes medications: Fasting and the bowel preparation period require adjustments to your insulin or oral hypoglycaemic agents. Your care team will provide specific guidance.
- Iron supplements: Should be stopped at least 5 to 7 days before the procedure as iron can coat the bowel lining and reduce visibility.
NSAIDs: Non-steroidal anti-inflammatory drugs increase bleeding risk and should be discussed with your doctor ahead of any polypectomy.
Arranging Transport
Because colonoscopy is performed under sedation, you will not be able to drive or travel unaccompanied for the remainder of the day. Please arrange for a responsible adult to collect you from Redus and accompany you home. Plan to rest for the rest of the day after the procedure.
What to Expect During Your Colonoscopy at Redus Health
Arrival and Pre-procedure Assessment
On arrival at Redus Center for Digestive Health, our nursing team will complete your admission, confirm the adequacy of your bowel preparation, check your vital signs, and review your consent. An intravenous cannula will be placed for the administration of sedation and any other medications required during the procedure. You will change into a hospital gown and be prepared for the procedure room.
Sedation
Colonoscopy is performed under conscious sedation — typically a combination of a sedative (such as midazolam) and an analgesic (such as fentanyl) — administered intravenously. The sedation makes you deeply relaxed and drowsy, and the majority of patients have little or no memory of the procedure. Your oxygen levels, heart rate, and blood pressure are monitored continuously throughout.
In selected cases, deeper sedation or propofol-based anaesthesia may be used. Your care team will advise on the most appropriate sedation approach for your individual situation.
Procedure
The colonoscopist will perform a brief external examination before gently introducing the colonoscope through the anus and advancing it progressively through the rectum and the full length of the colon to the caecum. Small amounts of air or carbon dioxide are introduced to gently expand the bowel and improve visibility.
The most detailed examination occurs as the colonoscope is slowly withdrawn — it is during withdrawal that most polyps and abnormalities are identified. If polyps are identified, they are removed immediately using appropriate technique. Biopsies are taken from any suspicious or inflamed areas. The entire procedure is recorded digitally for the permanent medical record.
Procedure Duration
A diagnostic colonoscopy typically takes 30 to 45 minutes. Procedures involving polypectomy, biopsy, or other therapeutic interventions may take 45 to 90 minutes. Including preparation and recovery, plan to spend 3 to 4 hours at Redus on the day of your procedure.
Recovery and Post-Procedure Care
Immediate Recovery
After the colonoscopy, you will be moved to the recovery area where nursing staff will monitor your vital signs and comfort as the sedation wears off — typically 30 to 60 minutes. You may feel bloated or gassy from the air introduced during the procedure. This is entirely normal and resolves quickly, particularly with gentle walking.
Going Home
Most patients are discharged on the same day. You must be accompanied home by a responsible adult and should not drive, operate machinery, drink alcohol, or make important decisions for the remainder of the day due to the residual effects of sedation.
Diet After Colonoscopy
After a diagnostic colonoscopy with biopsies, most patients can resume a normal diet from the same evening. After polypectomy — particularly removal of larger polyps — your doctor may recommend a soft or low-residue diet for 24 to 48 hours to allow the polypectomy site to heal, and may advise temporary avoidance of blood-thinning medications.
Normal Side Effects
Some mild, short-lived effects are entirely normal after colonoscopy:
- Bloating and gas: From air introduced during the procedure. Usually settles within a few hours. Walking gently helps.
- Mild abdominal cramping: Can occur, particularly after polypectomy. Usually resolves within 24 hours.
- Small amount of blood in the first stool after polypectomy: Minimal spotting is normal. However, significant or persistent rectal bleeding should be reported immediately.
- Drowsiness: From sedation. Resolves within a few hours.
Normal Side Effects
While complications after colonoscopy are uncommon, you should seek immediate medical attention or return to Redus if you experience:
- Significant rectal bleeding which is more than a small amount of spotting, or bleeding that continues
- Severe or worsening abdominal pain
- Abdominal distension (a hard or swollen abdomen)
- High fever or chills
- Persistent nausea and vomiting
- Inability to pass wind or open your bowels
Risks and Complications of Colonscopy
Colonoscopy is one of the safest and most commonly performed procedures in gastroenterology, with an excellent overall safety record. However, as with any invasive procedure, risks exist and patients should be fully informed:
Peforation
A perforation — a tear in the wall of the colon — is the most serious complication of colonoscopy, occurring in approximately 1 in 1,000 to 1 in 2,000 diagnostic colonoscopies, and slightly more frequently when polypectomy is performed. Perforation may require surgical repair and hospitalisation. The risk is higher in patients with severe diverticular disease, prior radiation to the pelvis, or significant adhesions.
Post-Polypectomy Bleeding
Bleeding from a polypectomy site can occur immediately or be delayed by up to 2 weeks after the procedure (delayed post-polypectomy bleeding). Most cases resolve spontaneously, but some require repeat colonoscopy to apply haemostasis. Patients on anticoagulant therapy are at higher risk, which is why these medications are typically paused before procedures involving polypectomy.
Missed Lesion (Incomplete Detection)
While colonoscopy is the gold standard for colonic examination, it is not infallible. Flat polyps, lesions behind folds, and those in areas of the colon not well visualised during a rapid withdrawal can occasionally be missed. Quality indicators such as adequate bowel preparation, high caecal intubation rate, and adequate withdrawal time significantly reduce this risk. Advanced imaging techniques including chromoendoscopy and narrow-band imaging (NBI) further improve polyp detection.
Adverse Reaction to Sedation
Reactions to the sedative medications used during colonoscopy are uncommon. Our team monitors your vital signs, oxygen levels, and consciousness continuously and is fully trained to manage any adverse event.
Post Polypectomy Syndrome
A small number of patients develop abdominal pain and fever after polypectomy without an identifiable perforation — this is called post-polypectomy syndrome, caused by local inflammation at the site of electrocautery. It is usually managed conservatively with antibiotics and resolves without surgery.
Splenic Injury
An extremely rare complication is injury to the spleen, which can occur during colonoscopy due to traction on the splenocolic ligament. This is very uncommon but may present as left-sided pain and may require surgical management.
Your gastroenterologist will explain the specific risks relevant to your procedure before you give your consent.
Colonoscopy vs. Other Colorectal Cancer Screening Options
Several alternatives to colonoscopy exist for colorectal cancer screening. Understanding how they compare helps patients and clinicians make informed decisions:
- CT Colonography (Virtual Colonoscopy): A CT scan of the colon performed after bowel preparation that creates detailed 3D images of the colon interior without the need for sedation or scope insertion. It can detect large polyps and cancers with good accuracy. However, it cannot remove polyps or take biopsies — any lesion found requires a follow-up colonoscopy. It also involves radiation exposure.
Faecal Immunochemical Test (FIT): A stool test that detects hidden blood from the colon. Simple, non-invasive, and performed at home, but detects blood rather than directly visualising lesions. A positive result requires follow-up colonoscopy.
Flexible Sigmoidoscopy: A shorter version of colonoscopy that examines only the rectum and sigmoid colon (the lower third of the large intestine), without bowel preparation and sometimes without sedation. It misses lesions in the right colon and transverse colon, which can be clinically significant.
Colonoscopy remains the gold standard because it is the only investigation that simultaneously examines the entire colon, identifies all significant lesions, and removes polyps in a single procedure. For patients who are symptomatic, who have risk factors, or in whom a thorough evaluation is required, colonoscopy is the most definitive option.
Colonoscopy at Redus Center for Digestive Health, Lagos
At Redus Center for Digestive Health in Lekki Phase 1, Lagos, colonoscopy is one of our core services and one of the most important things we do.
Colorectal cancer remains a significant and growing health concern in Nigeria and across Africa — and most cases are preventable or curable if detected early. We are committed to making high-quality colonoscopy accessible to patients across Lagos and Nigeria, and to bringing the same standard of care that patients expect from leading centres globally.
Our gastroenterologists perform colonoscopy using high-definition colonoscopes with advanced imaging capabilities, and maintain the high quality indicators — caecal intubation rate, adenoma detection rate, and withdrawal time — that distinguish excellent from adequate colonoscopy. We prioritise thorough bowel preparation guidance, patient comfort, and clear communication of results and next steps.
Whether you are coming for routine colorectal cancer screening, investigation of symptoms, or IBD surveillance, our team will guide you through the process with expertise and care.
Frequently Asked Questions About Colonoscopy
- Is colonoscopy painful?
Colonoscopy is performed under sedation, so the vast majority of patients experience little to no pain or discomfort during the procedure itself. Some patients experience mild cramping or a sense of pressure as the scope navigates the bends of the colon — this is well tolerated under sedation. The bowel preparation the day before is typically described as the most uncomfortable part of the process, though it is not painful. - How long does the colonoscopy take?
The procedure itself takes approximately 30 to 45 minutes for a diagnostic colonoscopy, and up to 90 minutes if polypectomy or other interventions are performed. Including preparation and recovery time, plan to be at Redus for approximately 3 to 4 hours in total. - Is the bowel preparation really necessary?
Yes — and it is one of the most important factors in colonoscopy quality. A poorly prepared colon means residual stool can hide polyps or other lesions, leading to missed diagnoses. An inadequately prepared colon may also mean the procedure cannot be completed and needs to be repeated. We understand the preparation is demanding, and our team will provide clear instructions and support to help you through it. - How often do I need a colonoscopy?
This depends on the findings. If no polyps or abnormalities are found in a well-prepared colon, a repeat colonoscopy for average-risk screening is typically recommended after 10 years. If polyps are found and removed, the surveillance interval is shortened — typically 3 to 5 years, depending on the number, size, and type of polyps. Patients with IBD or hereditary conditions require more frequent surveillance. Your gastroenterologist will recommend a specific interval based on your individual findings and risk profile. - Can colonoscopy detect all colorectal cancers?
Colonoscopy is the most accurate investigation available for detecting colorectal cancer and pre-cancerous polyps, but no test is 100% sensitive. Flat or serrated lesions can occasionally be missed, particularly in a poorly prepared or rapidly examined colon. This is why quality colonoscopy — with adequate preparation, complete examination to the caecum, and sufficient withdrawal time — is so important. - At what age should I have my first colonoscopy?
For average-risk individuals, colonoscopy screening is generally recommended from the age of 45. Those with a family history of colorectal cancer, personal history of polyps, or other risk factors should start earlier. If you are uncertain about when to begin screening, our team at Redus will help you assess your individual risk and recommend an appropriate starting age. - What happens if a polyp is found?
If a polyp is found during colonoscopy, the gastroenterologist will remove it during the same procedure in most cases — this is called polypectomy. The removed polyp is sent to a pathologist for analysis. You will receive the pathology results at a follow-up appointment, at which point your doctor will advise on any further surveillance needed based on the type and characteristics of the polyp. - Is colonoscopy available in Nigeria?
Yes — colonoscopy is available at Redus Center for Digestive Health in Lagos. We offer both diagnostic and therapeutic colonoscopy using high-definition equipment, performed by experienced consultant gastroenterologists. We welcome patients from across Lagos and Nigeria who require colonoscopy for screening, symptom investigation, or IBD surveillance.
Book Your Colonoscopy at Redus Center for Digestive Health
Whether you are due for routine colorectal cancer screening, have symptoms that need investigation, or require follow-up surveillance after previous polyps, we encourage you to contact our team at Redus Center for Digestive Health. Early detection saves lives — and colonoscopy is the most powerful tool we have for achieving it.
Our specialists will review your history and risk factors, prepare you thoroughly for the procedure, and communicate your results clearly. We are here to make the process as smooth, comfortable, and informative as possible.
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