The Pathogenesis of Chronic Diarrhoea After Treatment for Cancer in Cecum and the Ascending Colon

Many patients suffer from chronic diarrhoea after surgical treatment for cancer in the right side of the colon. The investigators' main hypothesis is that colon cancer patients with chronic diarrhoea have a higher risk of bile acid malabsorption compared with colon cancer patients without diarrhoea. The investigators also expect that a part of the cases of bile acid malabsorption is caused by underlying bacterial overgrowth in the small bowel. The investigators assume that patients with severe bile acid malabsorption have a lower value of FGF19 in the blood compared to patients with moderate or none bile acid malabsorption. Furthermore, it is assumed that patients with chronic diarrhoea and documented bile acid malabsorption after surgical treatment for right-sided colon cancer will get improved bowel function when treated with a bile acid binder, or antibiotics in case of bacterial overgrowth.

Patients with chronic diarrhoea after surgical treatment of right-sided colon cancer will be compared to patients without diarrhoea after right-sided colon cancer treatment. All patients will be asked to answer a short questionnaire regarding bowel function, and they will all have standard blood tests taken to exclude non-cancer related causes of diarrhoea. Besides these standard tests, the value of FGF19 will be measured in a blood sample from the fasting participants. All participants will undergo SeHCAT scan to determine the presence of bile acid malabsorption among right-sided colon cancer patients with and without diarrhoea. In addition, a glucose breath test will be performed to examine, if the patients have small intestinal bacterial overgrowth. Patients with a positive glucose breath test, and thus bacterial overgrowth, will be treated with antibiotics, followed by another SeHCAT scan, glucose breath test, and measurement of gastrointestinal transit time. In addition, they will be asked to complete the questionnaire regarding bowel function again. All cases with an abnormal SeHCAT scan will be treated with a bile acid binder, and the patients will be asked to complete the questionnaire one more time, and the GITT measurement will be repeated.

The diagnosis of bile acid malabsorption in cases vs. controls is determined by a positive SeHCAT scan.

This will be estimated based on self-reported symptoms: A bowel function questionnaire with 30 questions regarding different aspects of bowel function. The patients should state if they have the symptoms daily, 1-6 times per week, less than once a week, or never.

This will be estimated based on self-reported symptoms: the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 version 3.0. A questionnaire with 30 individual questions summing up to form one global health status, five functional subscales, three symptom scales and six single items addressing different aspects of quality of life. The scales range from 0-100 with a higher score representing a higher level of functioning or a higher degree of symptoms, respectively.

Inclusion Criteria: Primary adenocarcinoma in cecum or the ascending colon Right-sided hemicolectomy Understanding, speaking and reading Danish Exclusion Criteria: Previous major gastrointestinal, urological or gynaecological surgery or oncological treatment Radiation therapy Recurrence of colon cancer Metastasis Permanent stoma Pregnancy Reduced cognitive level that makes it plausible that the patient do not understand the study or is not capable of participation