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The Injured Cell
Published in Jeremy R. Jass, Understanding Pathology, 2020
Melanin is the dark brown or black pigment produced by the melanocytes of the skin and passed into adjacent epithelial cells. Melanin absorbs ultraviolet light and therefore protects the skin from damage. The amount of melanin produced by organelles called melanosomes is responsible for skin colour. Inflammatory skin lesions resulting in apoptosis are marked by the presence of melanophages (macrophages that have engulfed apoptotic bodies containing melanin). Regression of malignant melanoma is also associated with the presence of melanophages. ‘Melanosis coli’ in which the colonic musosal lining accumulates brown pigment is a misnomer. The pigment is related to lipfuscin and the condition results from chronic injury to the epithelium of the large bowel caused by purgative abuse.
Gastrointestinal Aspects of Eating Disorders
Published in Kevin W. Olden, Handbook of Functional Gastrointestinal Disorders, 2020
Bruce D. Waldholtz, Arnold E. Andersen
Persistent diarrhea may require evaluation for laxative abuse, not only in eating disorders but in any patient with unexplained diarrhea. Stools can be tested for phenolphthalein by alkalization using one drop of IN sodium hydroxide (NaOH) with 3 ml of stool supernate, which results in a positive pink to red color if present The presence of melanosis coli on sigmoidoscopy suggests prolonged use of laxatives. Of note, melanosis coli can occur in the sigmoid from anthracin (senna, cascara, and aloe), but not with phenolphthalein or bisacodyl, which are diphenolic laxatives (40).
The lower gastrointestinal tract, common conditions, and recommended treatments
Published in Simon R. Knowles, Laurie Keefer, Antonina A. Mikocka-Walus, Psychogastroenterology for Adults, 2019
In the majority of patients, constipation can be treated with alteration in lifestyle factors such as fluid and fibre intake (including addition of bulking agents i.e., psyllium husk) and exercise. Osmotic laxatives which hold fluid in the bowel lumen are generally second line followed by the use of stimulant laxatives. Patient are often concerned about the long-term use of these agents however, if prescribed in a controlled manner, there is no convincing studies that indicate long term use is harmful. Patients may develop discolouration of the colon (called ‘melanosis coli’); however, this has no long-term sequelae. Some patients may develop habituation with increasing doses, and clinicians should be alert to the potential for laxative abuse, often driven by underlying psychological disorders. In patients with IBS, the use of bulking agents or osmotic laxatives such as lactulose can be problematic as they are fermentable and can exacerbate symptoms of bloating or abdominal pain.
Therapeutic effects of Bombax ceiba flower aqueous extracts against loperamide-induced constipation in mice
Published in Pharmaceutical Biology, 2023
Liuping Wang, Shiyuan Xie, Xuan Jiang, Caini Xu, Youqiong Wang, Jianfang Feng, Bin Yang
More than 50% of patients fail to be cured, though the high global expenditure of constipation therapy annually (Zhang et al. 2021). Administration of laxatives and prokinetic agents (MTL agonists, 5-hydroxytryptamine modulators, opioid antagonists and chloride-channel activators) are common clinical treatments for constipation (Shin et al. 2014). However, long-term intake of these agents can be associated with complications, such as drug dependence, severe diarrhoea (Lu et al. 2021) hypotension, tachycardia, postural dizziness, melanosis coli, etc. (Ma et al. 2019). Therefore, it is urgently needed to find a new drug of hazard-free treatment for constipation. As an alternative treatment for constipation, traditional Chinese medicine is universally applied, safe and effective (Sun et al. 2020). Moreover, some studies suggest that multiple plant extracts could be applied to control constipation and there is hardly any side effect (Gilani et al. 2000; Han 2015; Lu et al. 2021).
Randomized, back-to-back trial of a new generation NBI with a high-definition white light (HQ290) for detecting colorectal polyps
Published in Scandinavian Journal of Gastroenterology, 2019
Haewon Kim, Hyeon Jeong Goong, Bong Min Ko, Yu Sik Myung, Yun Ho Jung, Seong Ran Jeon, Hyun Gun Kim, Moon Sung Lee
The flow chart of enrollment is presented in Figure 1. A total of 140 patients who underwent colonoscopy were randomization to the study arms. Seventy patients were randomly assigned in a 1:1 ratio to the 290-NBI or conventional HDWL group. At the end of the study, the data of twelve patients in the 290-NBI group, and eleven in the conventional HDWL group were excluded from the analysis. Twenty- three of the subjects did not complete the study protocol due to inadequate bowel preparation (9 in the NBI group and 10 in the HDWL group), obstruction due to colon cancer (1 in the NBI group) and melanosis coli (2 in the NBI group and 1 in the HDWL group). Finally, 58 and 59 patients were randomly assigned to the 290-NBI and HDWL groups, respectively. Table 1 shows the baseline characteristics of both groups. The median BBPS score, total insertion time, and withdrawal time were not significantly different between the 290-NBI and HDWL groups.
Colonic stasis and chronic constipation: Demystifying proposed risk factors for colon polyp formation in a spinal cord injury veteran population
Published in The Journal of Spinal Cord Medicine, 2018
Jason Colizzo, Jonathan Keshishian, Ambuj Kumar, Gitanjali Vidyarthi, Donald Amodeo
A similar retrospective study conducted by Meheroz et al. evaluated the presence of colonoscopic lesions in an SCI cohort of 71 patients. Their results indicated that the duration of SCI had a statistically significant correlation with total colonoscopic lesions (including polyps, hemorrhoids, and diverticula). In our study, neither the duration nor the level of injury correlated with polyp presence. Only age, an already well-established risk factor for polyp and CRC development, proved to correlate both with polyp and adenoma presence.35 A Korean case-control study by Han et al. also evaluated for variations in colonoscopic lesions in 25 SCI patients. They found the same incidence of colonoscopic lesions between this and a control group of 41 healthy individuals.36 This study, unfortunately, carries limited informative value in regards to constipation and CRC risk as the colonoscopic lesions included any abnormality seen during the endoscopy, such as hemorrhoids or melanosis coli, and were not specific to colon polyps as in our study.