When to call your doctor afterwards

In short

Most people feel uncomfortable but unworried in the hours after a coloscopy. Mild cramping, gas, a small amount of blood at the first bowel movement, and grogginess from sedation are expected. A small set of symptoms is different. The list below is the one to keep where you can see it for the first day or two.

What this page covers

The clear list of warning signs that warrant calling your endoscopy unit, your clinician, or — for a few of them — going directly to an emergency department. The expected, common symptoms that do not require a call. And the practical question of whom to call and when.

The warning signs, in plain language
The common symptoms that do not need a call
How long the most common complications take to appear
Who to call, and what to say
Special considerations after polyp removal

The warning signs

Call your endoscopy unit, your clinician, or an emergency service for any of the following. The right number is on your discharge paperwork; in many countries the unit operates a phone line for the days after a procedure. If a clinician is not available and a symptom is severe or progressing, go to the emergency department.

Heavy or recurrent rectal bleeding. A teaspoon of blood streaking the first stool can be normal, particularly after polyp removal. Bleeding that fills the toilet bowl, that recurs over multiple movements, that contains clots, or that continues for hours is not normal — call.
Severe or worsening abdominal pain. Cramps and gas pains are expected and ease with passing wind. Pain that is severe, that is sharp or constant, that worsens hour by hour, or that is much more intense than the test itself produced — call.
Fever above 38 °C (100.4 °F). Coloscopy by itself does not usually cause fever. A new fever in the day or days after the test, particularly with abdominal pain, warrants assessment.
Persistent vomiting. Mild nausea after sedation is common; persistent vomiting beyond the first hours, vomiting blood, or inability to keep fluids down — call.
Abdominal distension that is hard to the touch. A bloated, drum-tight abdomen, particularly with pain or fever, can signal a more serious complication and is a reason for urgent assessment.
Chest pain or shortness of breath. Either symptom after sedation deserves urgent evaluation — call an emergency service or go directly to an emergency department.
Signs of infection at the IV site. Spreading redness, increasing pain, warmth, or pus around where the cannula was placed should be reported.

Add to this list anything that simply feels seriously wrong. The rule of thumb on the unit is that pain or symptoms out of proportion to the test should be checked, even when the cause may turn out to be ordinary.

The common, expected symptoms

The following are typical and do not need a call by themselves. They tend to fade over hours or a day.

Cramping and gas. Air or carbon dioxide is used to open the bowel during the test. Most units now use carbon dioxide, which absorbs faster, but some passing of wind is universal afterwards. Walking helps.
Bloating. Closely related to gas. Diminishes over hours.
A small streak of blood with the first or second bowel movement. Common after polyp removal or biopsy. Usually settles.
Mild cramping or pressure with bowel movements for a day or two. Common, particularly if the bowel was very thoroughly emptied.
Grogginess and unreliable memory. Sedation effects can persist for the rest of the day. No driving, no signing important documents, no childcare alone.
Mild sore throat. Uncommon but possible if a mouth guard or oxygen prongs were used; resolves quickly.
Loose first stools. The bowel re-establishes its rhythm over the next day or two.

None of these is, by itself, a warning sign. A combination — for example, mild bleeding plus worsening pain plus fever — is.

Timing — when complications tend to appear

A coloscopy with no polyp removal has a very low complication rate; the symptoms above are mostly recovery from sedation. Coloscopy with polyp removal carries a slightly higher chance of bleeding from the polypectomy site and a small risk of perforation (a hole in the bowel wall). Bleeding most often occurs within the first day, but can occur up to two weeks later, particularly after removal of larger polyps or after EMR (endoscopic mucosal resection — lifting and removing a flat polyp). Perforation is uncommon and usually causes pain, fever, and abdominal distension within the first day or two.

Knowing this changes how to interpret symptoms over different time windows. Bleeding several days later is still worth a call. Severe pain a week later is still worth a call. Old advice that "if it has been more than 24 hours, you are in the clear" is too tidy.

Whom to call, and what to say

Your discharge paperwork should list a phone number for the endoscopy unit and a separate route for after-hours questions. Use those first. If neither is available and symptoms are urgent, your country's emergency service is the right line — your local emergency service is the best route in that case.

When you call, the team will ask three things. First, when was the procedure and where (the unit's name)? Second, were any polyps removed, and if so where and how (cold snare, hot snare, EMR)? Third, what symptoms are you having, when did they start, and how have they changed? Having your discharge paperwork in front of you makes the conversation much faster.

After polyp removal — a few specifics

If polyps were removed, particularly large or right-sided ones, your discharge instructions may include particular guidance: avoid heavy lifting and strenuous exercise for a number of days; resume blood thinners on a specific date rather than immediately; watch the resection site by recognising what bleeding from it would look like (red blood with a movement, sometimes with clots). The instructions vary by what was removed, by the technique used, and by your other medical conditions. They are written down for a reason — read them. If you cannot find them, the unit can resend them.

People who take blood thinners or antiplatelets — including warfarin, the direct oral anticoagulants, clopidogrel, and others — should follow the specific resumption plan they were given before discharge, not a generic schedule from a website. See blood thinners and antiplatelets for context, and remember that decisions to start or stop these medications are made with the clinician who prescribed them.

What to ask your clinician

What number do I call for problems in the first day, and what number for the days after?
Were any polyps removed, and is there anything specific I should watch the resection site for?
Are there activity restrictions, and for how many days?
When should I resume my regular medications, particularly blood thinners or antiplatelets?
What symptoms would you want me to call about, and which ones should send me to an emergency department directly?
How will my pathology results reach me, and when?
Is there a follow-up appointment, and is it scheduled?

Common worries, briefly addressed

I saw a small amount of blood. Is that bleeding?

A streak with the first stool, or a small spot on the paper, is common after biopsy or small polyp removal. Bleeding that worries the team is more substantial — clots, repeated movements with red blood, blood that fills the bowl, or bleeding that continues for hours. If you are unsure, photograph what you are seeing and call.

How much pain is too much?

Cramping that comes and goes with passing wind is normal. Pain that is sharp, constant, severe, or progressively worse — particularly with fever or distension — is the kind to call about. Compare it to the discomfort during the test itself: pain notably worse than that warrants assessment.

I feel feverish but the thermometer says 37.5 °C. Should I call?

Borderline temperatures in the first hours can reflect dehydration or recovery rather than infection. A clear fever above 38 °C, particularly with pain, deserves a call. A subjective sense of unwellness with no measurable fever can be re-checked in a few hours; if it worsens, call.

I am alone and worried. What now?

Call the unit's number first. If after hours, your country's emergency service or the urgent care number on your discharge paperwork. Do not drive yourself if symptoms are severe; ask for an ambulance. Most worries turn out to be nothing; the team would rather take a precautionary call than miss a real one.

When will pathology come back, and what if it doesn't?

Most pathology results return within one to three weeks, depending on the laboratory and the country. If you have not heard within the time frame your unit gave you, follow up. Pathology results can occasionally arrive in a portal but not generate a phone call.

Sources

American Society for Gastrointestinal Endoscopy — guidance on adverse events of coloscopy and post-procedure care
European Society of Gastrointestinal Endoscopy — guidelines on management of post-polypectomy complications
British Society of Gastroenterology — guidance on safe sedation, post-procedure care, and management of bleeding after polypectomy
American College of Gastroenterology — clinical guidelines on colorectal cancer screening and post-procedure considerations
National Institute for Health and Care Excellence — colorectal cancer guideline
U.S. Multi-Society Task Force on Colorectal Cancer — recommendations on post-coloscopy follow-up