Typical exam scenarios
A colon cancer occurs predominantly in people over 50 years of age. However, it can also affect younger patients, especially with a family history or hereditary tumor syndromes.
Opening question
What brings you here today?
Possible main complaints
Scenario 1:
“For several months I have had recurrent abdominal pain and diarrhea. Sometimes I have gone several days without a bowel movement beforehand.”
This so-called paradoxical diarrhea can occur with a tumor-related narrowing of the intestine: liquid stool passes the constriction while solid stool is retained.
Scenario 2:
“For about two to three weeks I have noticed blood in my stool.”
- Colon or rectal cancer
- Colon polyps
- Chronic inflammatory bowel disease
- Diverticulitis
- Infectious enterocolitis
- Anal fissure
- Hemorrhoidal disease
Possible signs include:
- new changes in bowel habits
- blood in the stool
- progressive or recurrent abdominal pain
- feeling of incomplete bowel evacuation
- unintentional weight loss and loss of appetite
- iron deficiency anemia without an identifiable cause
- positive family history
Right-sided colon cancers more often present with occult bleeding, iron deficiency anemia, fatigue or weight loss. Left-sided tumors cause, due to the narrower intestinal lumen, more often changes in stool, constipation, paradoxical diarrhea or signs of ileus. However, this allocation is not absolute.
Polyps are often asymptomatic and are frequently discovered incidentally during a screening colonoscopy. Occasionally they can cause bleeding. A family history increases the risk.
Typical are:
- often onset at a younger age
- relapsing course
- recurrent, sometimes bloody diarrhea
- abdominal pain
- mucus in stool and urgency
- possible extraintestinal symptoms, for example joint, skin, or eye changes
Long-standing ulcerative colitis or extensive Crohn colitis increases the risk for a colorectal cancer.
Typical are:
- predominantly older patients
- usually left-sided lower abdominal pain
- fever and elevated inflammatory markers
- constipation or diarrhea
- tenderness to pressure, possibly guarding
Signs include:
- acute onset
- pronounced watery or bloody diarrhea
- nausea and vomiting
- often fever and systemic signs of inflammation
- notable travel, food, or contact history
- possible antibiotic intake
The absence of fever does not reliably exclude an infectious enterocolitis.
Typical are:
- severe, sharp or burning pain during and after defecation
- bright red blood on toilet paper or on the stool
- often preceding constipation and hard stool
Typical are:
- bright red blood on toilet paper, on the stool, or in the toilet
- bleeding often painless
- itching, moisture, or foreign body sensation
- in advanced cases protrusion of tissue from the anal canal
Important: Hemorrhoids do not exclude a colon or rectal carcinoma. Newly occurring bleeding must therefore be further investigated depending on age, risk profile and accompanying symptoms.
Important questions in the medical history
Current complaints
- How long have the complaints been present?
- Did the complaints start suddenly or insidiously?
- Are they becoming progressively worse?
- Where is the abdominal pain located?
- Is there any relation to food intake or bowel movements?
- Have the frequency, consistency or shape of the stool changed?
- Do diarrhea and constipation alternate?
- Have you noticed blood, mucus, or black stool?
- Do you have the sensation of incomplete bowel evacuation?
- Do you have nausea, vomiting, fever, or nocturnal symptoms?
General warning signs
- Have you lost weight unintentionally?
- Are you suffering from loss of appetite?
- Do you feel tired or less able to perform?
- Have you noticed night sweats or fever?
Risk and family history
- Has there been colon cancer or colon polyps in your family?
- At what age was the disease diagnosed?
- Do you suffer from a chronic inflammatory bowel disease?
- Have you had colon polyps removed before?
- Have you participated in colon cancer screening?
- When was the last colonoscopy performed?
Physical examination
The examination includes:
- assessment of general condition and nutritional status
- check of vital signs
- inspection for pallor and signs of anemia
- abdominal examination: inspection, auscultation, percussion and palpation
- check for tenderness on pressure, guarding, masses or organomegaly
- digital rectal examination
- inspection of the anal region
- palpation of lymph nodes
Diagnostic approach
If colorectal cancer is suspected, the following investigations in particular may be considered:
- Laboratory tests: blood count, ferritin and transferrin saturation, inflammatory markers, electrolytes as well as liver and renal function tests
- Colonoscopy: the most important examination to visualize the entire colon and to take biopsies
- Histological examination: confirmation of the diagnosis
- Staging: usually CT of the chest, abdomen and pelvis
- For rectal carcinoma: for local spread assessment and therapy planning, a high-resolution MRI of the pelvis is performed in addition.
- CEA: primarily as a baseline value and for follow-up; not suitable for sole diagnosis or exclusion of a carcinoma
A stool test for occult blood is mainly used for early detection in asymptomatic individuals. With warning symptoms it does not replace the necessary endoscopic clarification.