Rectal Mechano-sensory Function in Patients with Carcinoid Diarrhea

Abstract

Background/AimsIn patients with neuroendocrine tumors, excessive production of serotonin and other amines may cause the carcinoid syndrome, which is mainly characterized by diarrhea and flushing. Little is known about the pathophysiology of carcinoid diarrhea. In several other groups of patients, diarrhea may be associated with rectal hypersensitivity and increased rectal tone. Therefore, the aim of the present study was to compare rectal sensitivity and compliance in patients with carcinoid diarrhea and in healthy subjects. MethodsTwelve patients (6 males, aged 54-78 years, median 65 years), with carcinoid diarrhea and 19 healthy subjects (7 males, aged 50-78 years, median 61 years) were included. Rectal mechanical and heat stimulation was used for assessment of rectal mechano-sensory properties. ResultsOverall, 5.3% higher temperatures were needed to elicit sensory responses in patients with carcinoid diarrhea than in healthy subjects (P = 0.015). Posthoc analyses revealed that the sensory threshold to heat was 48.1 ± 3.1 o C in patients vs 44.7 ± 4.7 o C in healthy subjects (P = 0.041). In contrast, patients and healthy subjects showed no overall differences in rectal sensory response to mechanical distension (P = 0.731) or rectal compliance (P = 0.990). ConclusionsPatients with carcinoid diarrhea have higher sensory thresholds to heat stimulation in comparison to healthy subjects, but normal rectal sensation to mechanical distension and normal compliance. Therefore, treatment of carcinoid diarrhea should aim at prolonging gastrointestinal transit and decreasing secretion, rather than modifying rectal mechano-sensory function.

Differential diagnosis of diarrhoea in patients with neuroendocrine tumours: A systematic review

“…Initial investigations into the cause of diarrhoea: Fourteen articles recommended or described the use of approaches to facilitate identification of patients who could be experiencing diarrhoea due to a cause other than CS[ 24 , 36 - 38 , 44 , 46 , 49 , 50 , 52 - 57 ]. Representative quotations for each sub-theme are presented in Figure 3 , and full details are available in .…”

“…This was most often conducted by measuring the radiographic progression or urinary 5-hydroxyindoleacetic acid levels to assess hormonal production, either in isolation or in combination with the assessment of patient history, presence of other symptoms of CS or physical examination[ 24 ]. Four articles reported assessment of patient history as an important first step in investigating diarrhoea[ 24 , 44 , 56 , 57 ]; for example, Gregersen et al[ 56 , 57 ] ruled out prior resection of the small intestine or colon as a cause for diarrhoea in patients with CS, as the diarrhoea was present before the surgery.…”

Combined primary neuroendocrine carcinoma and hepatocellular carcinoma of the liver in chronic hepatitis C: Case report and literature review

“…The clinical manifestations of NETs depend on the location of the tumor. Some NETs of the gastrointestinal tract, especially those associated with liver metastases, can manifest as carcinoid syndrome which is characterized by diarrhea, abdominal pain, and facial flushing [9]. In these cases, the investigation of gastrin, glucagon, VIP and chromogranin in blood or of serotonin metabolites such as 5-hydroxyindolacetic acid in 24-h urine can assist in the diagnosis [10].…”