Diarrhea, often caused by microorganisms, has been associated with high morbidity and mortality in Africa. Increased rates of antimicrobial-resistant pathogens have reignited the quest for alternative therapies. This review aimed at identifying medicinal plants used in the treatment of human diarrheal cases in Rwanda and analyzing their ethnobotany, ethnopharmacology, and phytochemistry. We searched PubMed/Medline, Google Scholar, ScienceDirect, and the Web of Science for published articles on medicinal plants used to treat diarrhea in Rwanda. Additionally, specialized herbarium documents of different institutes were reviewed. Articles were assessed for relevance, quality, and taxonomical accuracy before being included in this review. Overall, 63 species of medicinal plants belonging to 35 families were recorded. Asteraceae was the predominant family with six species, followed by Fabaceae and Lamiaceae, with five species each. The most reported species with anti-diarrheal properties were Vernonia amygdalina Delile, Tetradenia riparia (Hochst.) Codd, Clerodendrum myricoides R. Br., and Chenopodium ugandae (Aellen) Aellen. Leaves (66.7%) and roots (17.5%) were the commonly used plant parts in the preparation of medicine. Phytochemicals from medicinal plants with antidiarrheic activities were sesquiterpene lactones (V. amygdalina); terpene, sterols, saponosides, and flavonoids (C. ugandae); saponins and tannins (T. riparia); and tannins, flavonoids, and alkaloids (C. myricoides). Six studies tested the antimicrobial activities of the plants against bacteria and viruses known to cause diarrhea. Erythrina abyssinica, Euphorbia tirucalli, Dracaena afromontana, and Ficus thonningii are socio-culturally important. Further research on toxicity and posology is needed to ensure the safety of medicinal plants.

Plectranthus esculentus N.E.Br, locally known as "Impombo" is an important indigenous food crop in Rwanda which is currently endangered. One major factor that causes disappearance of this species, is the lower agronomic recommendations developed for growers and lack of information about nutrients contents leading to loss of interest in its cultivation. The objective of this study was to evaluate the response of living stone potato to inorganic manure fertilizers as an attempt to conserve and evaluate the potential of the crop food security crop, source of income, and its adaptation in the mid-altitude zone of Rwanda. The performance of the crop was evaluated under application of NPK (17:17:17) and farm yard manure fertilisers. These fertilizers were evaluated using a Randomized Completely Block Design (RCBD) with three replications. Analyse of variance showed that significant at (p < 0.01) was recorded in stem height, number of leaves but not high in stem diameter. The results indicated that vegetative growth and yield of plants in control plots were lower than what was obtained in treated plots. Production of living stone potato on large under application NPK (17.17.17) and organic fertlizer will ensure the conservation of genetic resources, food security, agricultural development and financial benefit to local farmers.