A colonoscopy is a standard medical procedure used to examine the large intestine. Although the procedure is often completed quickly under sedation, many people experience abdominal discomfort or pain afterward. This article explains the common causes of this discomfort and identifies the symptoms that warrant immediate medical attention.
The Primary Culprit Trapped Air and Bloating
The most common reason for immediate stomach discomfort following a colonoscopy is residual gas within the intestinal tract. To allow the physician to clearly view the colon lining, the large intestine must be expanded through insufflation. This involves introducing gas, such as room air or carbon dioxide (CO2), into the colon through the scope. This distension creates the necessary space for visualization but leaves gas behind after the scope is removed.
If ambient air is used, the body absorbs the gas slowly, causing feelings of fullness, distension, and sharp, migratory gas pains. Carbon dioxide is often preferred because it is absorbed by the bloodstream about 150 times faster than room air, which reduces post-procedure bloating and pain. The residual gas stretches the intestinal wall, causing bloating and pressure until it is naturally passed. Passing flatus is the most effective way to eliminate this discomfort, which usually resolves within a few hours. Simple activities like walking can help mobilize this trapped gas and facilitate its release.
Other Sources of Discomfort Cramping and Irritation
Other sources of abdominal pain relate to the preparation phase and mechanical interaction with the colon tissue. The aggressive laxative regimen required for bowel preparation often causes minor mucosal irritation that persists after the procedure. The large volume of fluid and chemicals used to clear the bowel can leave the intestinal lining temporarily sensitive, leading to generalized soreness and spasms. This chemical irritation causes residual discomfort distinct from the sharp pains associated with trapped air.
Cramping may also occur as the colon muscles, hyperactive during preparation, begin to return to their normal motility patterns. The physical movement of the endoscope through the colon can also cause minor physical irritation. This is particularly noticeable around sharp bends or curves, where the scope must navigate carefully.
If a polyp was removed or a biopsy was taken, the intervention site can cause localized soreness. This is essentially a small wound within the colon lining that may result in mild, transient cramping or a dull ache for a day or two. These recovery symptoms are distinct from gas pain and typically subside as the bowel heals and motility normalizes within 48 hours.
When to Call the Doctor Warning Signs
While mild discomfort is expected, certain symptoms suggest a more significant issue requiring immediate medical evaluation. A concerning sign is severe abdominal pain that is distinctly worsening rather than gradually improving after the procedure. Pain that becomes generalized, rigid, or unbearable may indicate a serious complication, such as a bowel perforation, which requires emergency intervention.
A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, especially when accompanied by chills, should prompt a call to the physician. Fever can be a sign of infection developing within the abdominal cavity or the bloodstream, requiring prompt antibiotic treatment. These symptoms represent a systemic response to an underlying problem that routine discomfort does not cause.
Minor spotting or small amounts of blood on toilet paper is often normal, especially if polyps were removed, but persistent or heavy rectal bleeding is not. If you pass several large clots or have a continuous flow of bright red blood, contact your doctor immediately. This could indicate delayed post-polypectomy hemorrhage, which can sometimes occur up to two weeks after the procedure.
Other warning signs include persistent vomiting that prevents keeping fluids down, or signs of shock, such as lightheadedness, dizziness, or a rapid heart rate. Recognizing these specific symptoms and seeking timely professional advice ensures that any potential complication is addressed quickly.