The clinical features of colorectal carcinoma manifest due to the tumor itself or due to a local and metastatic spread of the tumor. However, it must be remembered that a certain proportion of patients are asymptomatic and are only detected incidentally or during screening. The common clinical manifestations arising from the tumor are rectal bleeding, change in bowel habits, rectal/ abdominal mass, anemia, weight loss, abdominal pain, pelvic pain, and urinary symptoms [1] [2] [3].

Rectal bleeding is a common manifestation. This presents as either drops of fresh blood or as blood streaked on the stools [4]. Dark-colored blood, in general, is more likely to be associated with colorectal cancer than bright red-colored blood [5]. Sometimes, bleeding can occur in an occult fashion without the patient having taken any notice. However, long-term blood loss, even in minute quantities, leads to symptoms of anemia [6].

Change in bowel habits is yet another common symptom. This presents as diarrhea, constipation, a sensation of incomplete evacuation, and tenesmus.

Other symptoms due to a local and metastatic spread of colorectal carcinoma are the pelvic pain, back pain, urinary symptoms, and yellowish discoloration of the sclera.

Related signs that may be identified on general physical examination are cachexia, paleness, and jaundice. Abdominal examination may help in the detection of ascites and hepatomegaly.

Digital rectal examination is the most specific test in physical examination and it may reveal the size of the tumor and features such as ulceration and local spread. It may also reveal a change in anal sphincter tone, which will indicate whether the tumor has spread locally to involve the nerves. Proctoscopy will help to further visualize the tumor.

• Cervical Lymphadenopathy

  A 61-year-old man presented with cervical lymphadenopathy 18 years after undergoing surgery for right lung carcinoma [poorly differentiated adenocarcinoma stage IIb (T3N0M0)]. [ncbi.nlm.nih.gov]

• Weight Loss

  A 16-year-old girl presented to our unit with crampy abdominal pain, change in bowel habit, a subjective impression of weight loss and a single episode of haematochezia. [ncbi.nlm.nih.gov]

  The common clinical manifestations arising from the tumor are rectal bleeding, change in bowel habits, rectal/ abdominal mass, anemia, weight loss, abdominal pain, pelvic pain, and urinary symptoms. Rectal bleeding is a common manifestation. [symptoma.com]

• Fatigue

  Four months later the patient was admitted to the gastroenterology department for further examination because of chronic fatigue, subfebrile temperature and a positive fecal occult blood test. [ncbi.nlm.nih.gov]

  Common in Colorectal Cancer survivors Consider evaluating for alternative Fatigue cause (e.g Anemia, Hypothyroidism ) VIII. [fpnotebook.com]

  Diarrhea or constipation A feeling that your bowel does not empty completely Blood (either bright red or very dark) in your stool Stools that are narrower than usual Frequent gas pains or cramps, or feeling full or bloated Weight loss with no known reason Fatigue [medlineplus.gov]

  Common side effects of chemotherapy include: hair loss nausea fatigue vomiting Combination therapies often use multiple types of chemotherapy or combine chemotherapy with other treatments. [medicalnewstoday.com]

• Weakness

  RESULTS: Our results confirm that the nuclear VDR expression is strongest in normal colorectal mucosa and in hyper plastic polyps, is gradually weakened in low and high grade adenoma while it is extremely weak or absent in colorectal carcinoma. [ncbi.nlm.nih.gov]

  As a person loses blood over time, they will develop anemia, or lowered red blood cell count, causing them to feel tired and weak. Unexplained weight loss is another sign that a cancer may be present, but this is by no means exclusive to CRC. [pharma.bayer.com]

  Shared Symptoms and Diagnosis Both colon and rectal cancer are likely to cause many of the same symptoms, including: Stomach or gas pains Constipation or diarrhea Black, dark, or red colored stools, which can all indicate blood Feeling weak or tired Doctors [webmd.com]

  The intensity score (0, no immunoreactivity; 1, weak; 2, strong) was used as well as the extent score (1, 1-10%; 2, 10-50%; and 3, 50-100%). [omicsonline.org]

  “go” to save your life) that lasts for more than a few days Unintended or unexplained weight loss (or weight gain) Vomiting Narrow stools – poo looks pencil-thin Change in stools – poo just looks different, smells different Gas, bloating and cramps Weakness [colonclub.com]

• Diarrhea

  This presents as diarrhea, constipation, a sensation of incomplete evacuation, and tenesmus. [symptoma.com]

  […] adenomatous polyposis syndrome (FAP) Gardner syndrome variant Turcot syndrome variant Peutz-Jeghers syndrome hereditary non-polyposis colon cancer syndrome (HNPCC) Clinical presentation is typically insidious: altered bowel habit (constipation and/or diarrhea [radiopaedia.org]

• Constipation

  This presents as diarrhea, constipation, a sensation of incomplete evacuation, and tenesmus. [symptoma.com]

  Constipation is commonly prevalent in Kuwait more so in females than males [ 45 ]. Efforts to avoid the constipation may help minimize the CRC risk in this and other similar populations. [bmccancer.biomedcentral.com]

  […] include: familial adenomatous polyposis syndrome (FAP) Gardner syndrome variant Turcot syndrome variant Peutz-Jeghers syndrome hereditary non-polyposis colon cancer syndrome (HNPCC) Clinical presentation is typically insidious: altered bowel habit (constipation [radiopaedia.org]

• Abdominal Pain

  A 16-year-old girl presented to our unit with crampy abdominal pain, change in bowel habit, a subjective impression of weight loss and a single episode of haematochezia. [ncbi.nlm.nih.gov]

  The common clinical manifestations arising from the tumor are rectal bleeding, change in bowel habits, rectal/ abdominal mass, anemia, weight loss, abdominal pain, pelvic pain, and urinary symptoms. Rectal bleeding is a common manifestation. [symptoma.com]

  Clinical Features The common clinical features of bowel cancer include change in bowel habit, rectal bleeding, weight loss*, abdominal pain, and iron-deficiency anaemia. [teachmesurgery.com]

• Rectal Bleeding

  The common clinical manifestations arising from the tumor are rectal bleeding, change in bowel habits, rectal/ abdominal mass, anemia, weight loss, abdominal pain, pelvic pain, and urinary symptoms. Rectal bleeding is a common manifestation. [symptoma.com]

  Only increased awareness of this malignancy in this age-group and a high index of suspicion can help when a child complains of persistent pain of abdomen, altered bowel habits or rectal bleeding, and may provide diagnosis at an earlier stage, thereby [ncbi.nlm.nih.gov]

  bleeding Occasionally metastatic disease may be the first sign. [radiopaedia.org]

• Blood in Stool

  […] in stool (although not always visible.) [colonclub.com]

  stools Colicky abdominal pain due to obstruction Rectum (50%) and sigmoid (30%) Hematochezia Stool caliber (pencil-shaped stool) Rectal pain Tenesmus Flatulence with involuntary stool loss Symptoms according to stage of disease Colorectal cancer must [amboss.com]

  Blood in the stool, even blood that cannot be seen by the naked eye (occult blood—see Stool Occult Blood Tests), can be a sign of cancer. Usually, the stool is tested every year. [merckmanuals.com]

  […] in stool sample Annually No bowel preparation No direct risk to bowel Sample can be collected at home Dietary restrictions before testing Cannot detect precancerous changes Detects any blood, not just from cancers but from food or dental procedures May [labtestsonline.org]

• Cutaneous Manifestation

  Cutaneous manifestations of visceral carcinomas are scarce, occurring in around 0.7-12% of internal malignancies. Lung cancer is one of the most common sources of skin metastasis, particularly in male patients. [ncbi.nlm.nih.gov]

• Testicular Mass

  The authors report a case of 35-year-old man with right testicular mass. Contrast-enhanced CT scan (CECT) of testes showed testicular mass with ascitis and enlargement of retroperitoneal lymphnodes. [ncbi.nlm.nih.gov]

Screening is an important part of diagnosing colorectal carcinoma and has led to its decline in incidence over time [7]. The recommended mode of screening is colonoscopy every ten years from 50 years of age [8].

The mainstay of diagnosing colorectal carcinoma is colonoscopy followed by biopsy of the suspicious lesions.

Further testing is aimed at grading and staging the tumor that may have an implication on management.

Blood studies such as complete blood count, renal function tests, and hepatic function tests are important too as they serve as indicators of organ damage.

Serum carcinoembryonic antigen (CEA) levels give an insight into prognosis.

Other tests which must be considered are ultrasonography (US) and magnetic resonance imaging (MRI) to assess the spread of the disease.

A chest radiography and abdominal computed tomography (CT) may also help to assess metastatic spread. Positron emission tomography (PET) scans are gaining popularity as an effective imaging modality to detect metastatic lesions.

Molecular genetic testing to detect various genetic mutations is rapidly gaining evidence as a guide for the treatment of metastatic colorectal cancer.

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3. Panzuto F, Chiriatti A, Bevilacqua S, et al. Symptom-based approach to colorectal cancer: survey of primary care physicians in Italy. Dig Liver Dis. 2003;35(12):869–875.
4. Robertson R, Campbell C, Weller DP, et al. Predicting colorectal cancer risk in patients with rectal bleeding. Br J Gen Pract. 2006;56(531):763–767.
5. Ellis BG, Thompson MR. Factors identifying higher risk rectal bleeding in general practice. Br J Gen Pract. 2005;55(521):949–955.
6. Hamilton W, Lancashire R, Sharp D, Peters TJ, Cheng KK, Marshall T. The importance of anaemia in diagnosing colorectal cancer: a case-control study using electronic primary care records. Br J Cancer. 2008;98(2):323–327.
7. American Cancer Society. Cancer Facts & Figures 2016. American Cancer Society. Available at https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/cancer-facts-figures-2016.html
8. Rex DK, Johnson DA, Anderson JC, Schoenfeld PS, Burke CA, Inadomi JM. American College of Gastroenterology guidelines for colorectal cancer screening 2009 [corrected]. Am J Gastroenterol. 2009;104 (3):739-750.