The Collaborative International Dictionary of English v.0.48:

Dysentery \Dys"en*ter*y\, n. [L. dysenteria, Gr. ?; dys- ill,
   bad + ?, pl. ?, intestines, fr. 'ento`s within, fr. ? in,
   akin to E. in: cf. F. dysenterie. See Dys, and In.]
   (Med.)
   A disease attended with inflammation and ulceration of the
   colon and rectum, and characterized by griping pains,
   constant desire to evacuate the bowels, and the discharge of
   mucus and blood.
   [1913 Webster]

   Note: When acute, dysentery is usually accompanied with high
         fevers. It occurs epidemically, and is believed to be
         communicable through the medium of the alvine
         discharges.
         [1913 Webster]

WordNet (r) 3.0 (2006):

dysentery
    n 1: an infection of the intestines marked by severe diarrhea

Moby Thesaurus II by Grady Ward, 1.0:

227 Moby Thesaurus words for "dysentery":
   African lethargy, Asiatic cholera, BM, Chagres fever,
   German measles, Haverhill fever, abscess,
   acute articular rheumatism, ague, alkali disease, amebiasis,
   amebic dysentery, anemia, ankylosis, anoxia, anthrax, apnea,
   asphyxiation, asthma, ataxia, atrophy, bacillary dysentery,
   backache, bastard measles, black death, black fever,
   blackwater fever, bleeding, blennorhea, bloody flux,
   bowel movement, breakbone fever, brucellosis, bubonic plague,
   cachectic fever, cachexia, cachexy, cardialgia, catharsis,
   cerebral rheumatism, chicken pox, chill, chills, cholera,
   cholera morbus, colic, constipation, convulsion, costiveness,
   coughing, cowpox, crap, cyanosis, dandy fever, deer fly fever,
   defecation, dejection, dengue, dengue fever, diarrhea, diphtheria,
   dizziness, dropsy, dumdum fever, dyspepsia, dyspnea, edema,
   elephantiasis, emaciation, encephalitis lethargica, enteric fever,
   erysipelas, evacuation, fainting, famine fever, fatigue, fever,
   fibrillation, five-day fever, flu, flux, frambesia,
   glandular fever, gripe, gripes, grippe, growth, hansenosis,
   heartburn, hemorrhage, hepatitis, herpes, herpes simplex,
   herpes zoster, high blood pressure, histoplasmosis, hookworm,
   hydrophobia, hydrops, hypertension, hypotension, icterus,
   indigestion, infantile paralysis, infectious mononucleosis,
   inflammation, inflammatory rheumatism, influenza, insomnia,
   irregularity, itching, jail fever, jaundice, jungle rot, kala azar,
   kissing disease, labored breathing, lepra, leprosy, leptospirosis,
   lientery, loa loa, loaiasis, lockjaw, loose bowels,
   low blood pressure, lumbago, madness, malaria, malarial fever,
   marasmus, marsh fever, measles, meningitis, milzbrand, movement,
   mumps, nasal discharge, nausea, necrosis, obstipation, ornithosis,
   osteomyelitis, pain, paralysis, paratyphoid fever, parotitis,
   parrot fever, pertussis, pneumonia, polio, poliomyelitis,
   polyarthritis rheumatism, ponos, pruritus, psittacosis, purgation,
   purge, pyrosis, rabbit fever, rabies, rash, rat-bite fever,
   relapsing fever, rheum, rheumatic fever, rickettsialpox, ringworm,
   rubella, rubeola, runs, scarlatina, scarlet fever, schistosomiasis,
   sclerosis, seizure, septic sore throat, shingles, shit, shits,
   shock, skin eruption, sleeping sickness, sleepy sickness, smallpox,
   snail fever, sneezing, sore, spasm, splenic fever, spotted fever,
   stool, strep throat, swamp fever, tabes, tachycardia, tetanus,
   thrush, tinea, trench fever, trench mouth, trots, tuberculosis,
   tularemia, tumor, turistas, typhoid, typhoid fever, typhus,
   typhus fever, undulant fever, upset stomach, vaccinia, varicella,
   variola, venereal disease, vertigo, viral dysentery, voidance,
   vomiting, wasting, whooping cough, yaws, yellow fever, yellow jack,
   zona, zoster