Flexible Sigmoidoscopy: What It Is, How to Prepare & who should consider
A flexible sigmoidoscopy is a minimally invasive procedure that allows your gastroenterologist to examine the lower portion of your large intestine — specifically the sigmoid colon and rectum — using a thin, flexible tube with a high-definition camera attached to its tip. It’s one of the most direct, accurate ways to investigate symptoms like rectal bleeding, persistent diarrhea, unexplained abdominal cramping, or changes in bowel habits that haven’t resolved on their own
What Is a Flexible Sigmoidoscopy?
A flexible sigmoidoscopy uses a slender, lighted scope called a sigmoidoscope — about the width of your index finger — to examine roughly the lower one-third of the colon. That includes the sigmoid colon, the descending colon, and the rectum.
During the procedure, the scope transmits live images to a monitor, giving your gastroenterologist a direct, clear view of the colon lining. If anything suspicious is spotted — a polyp, a patch of inflammation, an abnormal growth — a small tissue sample (biopsy) can be taken during the same procedure for laboratory analysis.
The procedure typically takes 10 to 20 minutes. Because it examines only the lower colon rather than the full length of the large intestine, it’s faster, requires less extensive preparation, and often doesn’t require sedation — making it more accessible for many patients.
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What Conditions Does Flexible Sigmoidoscopy Diagnose?
A flexible sigmoidoscopy helps evaluate and diagnose a wide range of conditions affecting the lower digestive tract:
Rectal bleeding is the most common reason a sigmoidoscopy is ordered. Whether the blood is bright red on toilet paper, coating the stool, or mixed into it — a direct visual examination is the only reliable way to identify the source. Hemorrhoids and anal fissures are often confirmed this way, but so are more significant causes like polyps, IBD, or rectal cancer.
Inflammatory bowel disease (IBD) — including ulcerative colitis and Crohn’s disease affecting the lower colon — produces visible inflammation, ulceration, and changes in tissue texture that are clearly identifiable during sigmoidoscopy. Biopsies taken during the procedure confirm the diagnosis.
Colorectal polyps in the sigmoid colon and rectum are found and can be removed during the procedure. Any polyp removed is sent to pathology to determine whether it’s benign, precancerous, or malignant.
Proctitis — inflammation of the rectum from any cause — is directly visible and biopsied for accurate diagnosis and treatment planning.
Chronic diarrhea or constipation that hasn’t responded to standard management warrants structural evaluation. Flexible sigmoidoscopy rules out anatomical causes in the lower colon and rectum.
Unexplained abdominal pain focused in the lower left abdomen — the area the sigmoid colon occupies — may be evaluated with sigmoidoscopy alongside other diagnostic tools.
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How to Prepare for a Flexible Sigmoidoscopy
Preparation for flexible sigmoidoscopy is significantly simpler than preparation for a full colonoscopy — which is one reason patients often prefer it when their symptoms are localized to the lower bowel.
The Day Before
Unlike colonoscopy, you typically do not need to follow a special diet the day before a flexible sigmoidoscopy. Your doctor will give you specific instructions, but in most cases a normal diet the day before is acceptable.
The Day of the Procedure
Enema preparation is the standard approach for flexible sigmoidoscopy. You’ll use one or two over-the-counter enemas (such as Fleet Saline Enema) about one to two hours before your appointment time, at home. This clears the lower colon sufficiently for clear visualization.
Your doctor’s office will give you the exact timing and type of enema to use — follow those instructions carefully. A clean lower colon directly affects how thoroughly Dr. Shakoor can examine the tissue, so prep quality matters.
Is Flexible Sigmoidoscopy Painful?
This is one of the most commonly searched questions — and the honest answer is: most patients experience mild discomfort rather than pain.
The most common sensation is a feeling of pressure or bloating as air is introduced into the colon. Some patients feel brief cramping when the scope navigates the curves of the sigmoid colon. These sensations are temporary and resolve quickly as the scope is removed.
Because sedation is usually not required, you remain fully awake and can communicate with Dr. Shakoor and the nursing team throughout the procedure. Most patients are surprised by how tolerable it is compared to what they anticipated.
If you have a low pain tolerance, significant anxiety, or a prior difficult experience with a similar procedure — let your doctor know in advance. Mild sedation can be arranged in certain circumstances.
Who Should Consider a Flexible Sigmoidoscopy?
Flexible sigmoidoscopy is appropriate for:
- Adults experiencing rectal bleeding not yet evaluated by a gastroenterologist
- Patients with persistent lower abdominal pain or unexplained changes in bowel habits
- Adults with known lower GI conditions requiring periodic surveillance — such as proctitis or distal ulcerative colitis
- Average-risk adults who prefer a less intensive screening option and are not candidates for or cannot access colonoscopy — when combined with annual FIT testing, sigmoidoscopy every 5 years is a recognized USPSTF screening strategy
Flexible sigmoidoscopy is not appropriate as a standalone screening tool for:
- Patients with a personal or family history of colorectal cancer or adenomatous polyps
- Patients with IBD involving the full colon
- Patients with hereditary syndromes (Lynch syndrome, FAP)
- Anyone with symptoms suggesting pathology in the upper or right colon
If you’re unsure which procedure is right for your situation, a consultation with Dr. Shakoor will clarify the most appropriate diagnostic or screening path based on your individual history and symptoms.
Schedule Your Flexible Sigmoidoscopy in Conyers, GA
At Colon & Digestive Health Specialists, we understand that lower GI symptoms are disruptive, sometimes frightening, and deserve a real answer — not a “wait and see” approach. Dr. Karim Shakoor and our team provide thorough, expert diagnostic care using advanced endoscopic tools in our Joint Commission-accredited Eastside Endoscopy Center.
We serve patients across Conyers, Rockdale County, Newton County, and Henry County, Georgia, with convenient scheduling and prompt appointments for patients experiencing new or concerning digestive symptoms.
Keep Reading: Flexible Sigmoidoscopy vs. Colonoscopy: Which Screening Test Do You Need?
For Life-Threatening Emergencies Call 911
Our location
Colon & Digestive Health Specialists 1805 Honey Creek Commons, Ste B, Conyers GA 30013